Compile and render Synapse's docs into a browsable, mobile-friendly and searchable website (#10086)

35 files changed, 978 insertions, 54 deletions

diff --git a/.github/workflows/docs.yaml b/.github/workflows/docs.yaml
new file mode 100644
index 0000000000..a746ae6de3
--- /dev/null
+++ b/.github/workflows/docs.yaml
@@ -0,0 +1,31 @@
+name: Deploy the documentation
+
+on:
+  push:
+    branches:
+      - develop
+
+  workflow_dispatch:
+
+jobs:
+  pages:
+    name: GitHub Pages
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v2
+
+      - name: Setup mdbook
+        uses: peaceiris/actions-mdbook@4b5ef36b314c2599664ca107bb8c02412548d79d # v1.1.14
+        with:
+          mdbook-version: '0.4.9'
+
+      - name: Build the documentation
+        run: mdbook build
+
+      - name: Deploy latest documentation
+        uses: peaceiris/actions-gh-pages@068dc23d9710f1ba62e86896f84735d869951305 # v3.8.0
+        with:
+          github_token: ${{ secrets.GITHUB_TOKEN }}
+          keep_files: true
+          publish_dir: ./book
+          destination_dir: ./develop
diff --git a/.gitignore b/.gitignore
index 295a18b539..6b9257b5c9 100644
--- a/.gitignore
+++ b/.gitignore
@@ -46,3 +46,6 @@ __pycache__/
 /docs/build/
 /htmlcov
 /pip-wheel-metadata/
+
+# docs
+book/
diff --git a/MANIFEST.in b/MANIFEST.in
index 25d1cb758e..0522319c40 100644
--- a/MANIFEST.in
+++ b/MANIFEST.in
@@ -40,6 +40,7 @@ exclude mypy.ini
 exclude sytest-blacklist
 exclude test_postgresql.sh
 
+include book.toml
 include pyproject.toml
 recursive-include changelog.d *
 
diff --git a/book.toml b/book.toml
new file mode 100644
index 0000000000..fa83d86ffc
--- /dev/null
+++ b/book.toml
@@ -0,0 +1,39 @@
+# Documentation for possible options in this file is at
+# https://rust-lang.github.io/mdBook/format/config.html
+[book]
+title = "Synapse"
+authors = ["The Matrix.org Foundation C.I.C."]
+language = "en"
+multilingual = false
+
+# The directory that documentation files are stored in
+src = "docs"
+
+[build]
+# Prevent markdown pages from being automatically generated when they're
+# linked to in SUMMARY.md
+create-missing = false
+
+[output.html]
+# The URL visitors will be directed to when they try to edit a page
+edit-url-template = "https://github.com/matrix-org/synapse/edit/develop/{path}"
+
+# Remove the numbers that appear before each item in the sidebar, as they can
+# get quite messy as we nest deeper
+no-section-label = true
+
+# The source code URL of the repository
+git-repository-url = "https://github.com/matrix-org/synapse"
+
+# The path that the docs are hosted on
+site-url = "/synapse/"
+
+# Additional HTML, JS, CSS that's injected into each page of the book.
+# More information available in docs/website_files/README.md
+additional-css = [
+    "docs/website_files/table-of-contents.css",
+    "docs/website_files/remove-nav-buttons.css",
+    "docs/website_files/indent-section-headers.css",
+]
+additional-js = ["docs/website_files/table-of-contents.js"]
+theme = "docs/website_files/theme"
\ No newline at end of file
diff --git a/changelog.d/10086.doc b/changelog.d/10086.doc
new file mode 100644
index 0000000000..2200579012
--- /dev/null
+++ b/changelog.d/10086.doc
@@ -0,0 +1 @@
+Add initial infrastructure for rendering Synapse documentation with mdbook.
diff --git a/docs/README.md b/docs/README.md
index 3c6ea48c66..e113f55d2a 100644
--- a/docs/README.md
+++ b/docs/README.md
@@ -1,7 +1,72 @@
 # Synapse Documentation
 
-This directory contains documentation specific to the `synapse` homeserver.
+**The documentation is currently hosted [here](https://matrix-org.github.io/synapse).**
+Please update any links to point to the new website instead.
 
-All matrix-generic documentation now lives in its own project, located at [matrix-org/matrix-doc](https://github.com/matrix-org/matrix-doc)
+## About
 
-(Note:  some items here may be moved to [matrix-org/matrix-doc](https://github.com/matrix-org/matrix-doc) at some point in the future.)
+This directory currently holds a series of markdown files documenting how to install, use
+and develop Synapse, the reference Matrix homeserver. The documentation is readable directly
+from this repository, but it is recommended to instead browse through the
+[website](https://matrix-org.github.io/synapse) for easier discoverability.
+
+## Adding to the documentation
+
+Most of the documentation currently exists as top-level files, as when organising them into
+a structured website, these files were kept in place so that existing links would not break.
+The rest of the documentation is stored in folders, such as `setup`, `usage`, and `development`
+etc. **All new documentation files should be placed in structured folders.** For example:
+
+To create a new user-facing documentation page about a new Single Sign-On protocol named
+"MyCoolProtocol", one should create a new file with a relevant name, such as "my_cool_protocol.md".
+This file might fit into the documentation structure at:
+
+- Usage
+  - Configuration
+    - User Authentication
+      - Single Sign-On
+        - **My Cool Protocol**
+
+Given that, one would place the new file under
+`usage/configuration/user_authentication/single_sign_on/my_cool_protocol.md`.
+
+Note that the structure of the documentation (and thus the left sidebar on the website) is determined
+by the list in [SUMMARY.md](SUMMARY.md). The final thing to do when adding a new page is to add a new
+line linking to the new documentation file:
+
+```markdown
+- [My Cool Protocol](usage/configuration/user_authentication/single_sign_on/my_cool_protocol.md)
+```
+
+## Building the documentation
+
+The documentation is built with [mdbook](https://rust-lang.github.io/mdBook/), and the outline of the
+documentation is determined by the structure of [SUMMARY.md](SUMMARY.md).
+
+First, [get mdbook](https://github.com/rust-lang/mdBook#installation). Then, **from the root of the repository**,
+build the documentation with:
+
+```sh
+mdbook build
+```
+
+The rendered contents will be outputted to a new `book/` directory at the root of the repository. You can
+browse the book by opening `book/index.html` in a web browser.
+
+You can also have mdbook host the docs on a local webserver with hot-reload functionality via:
+
+```sh
+mdbook serve
+```
+
+The URL at which the docs can be viewed at will be logged.
+
+## Configuration and theming
+
+The look and behaviour of the website is configured by the [book.toml](../book.toml) file
+at the root of the repository. See
+[mdbook's documentation on configuration](https://rust-lang.github.io/mdBook/format/config.html)
+for available options.
+
+The site can be themed and additionally extended with extra UI and features. See
+[website_files/README.md](website_files/README.md) for details.
diff --git a/docs/SUMMARY.md b/docs/SUMMARY.md
new file mode 100644
index 0000000000..8f39ae0270
--- /dev/null
+++ b/docs/SUMMARY.md
@@ -0,0 +1,87 @@
+# Summary
+
+# Introduction
+- [Welcome and Overview](welcome_and_overview.md)
+
+# Setup
+  - [Installation](setup/installation.md)
+  - [Using Postgres](postgres.md)
+  - [Configuring a Reverse Proxy](reverse_proxy.md)
+  - [Configuring a Turn Server](turn-howto.md)
+  - [Delegation](delegate.md)
+
+# Upgrading
+  - [Upgrading between Synapse Versions](upgrading/README.md)
+  - [Upgrading from pre-Synapse 1.0](MSC1711_certificates_FAQ.md)
+
+# Usage
+  - [Federation](federate.md)
+  - [Configuration](usage/configuration/README.md)
+    - [Homeserver Sample Config File](usage/configuration/homeserver_sample_config.md)
+    - [Logging Sample Config File](usage/configuration/logging_sample_config.md)
+    - [Structured Logging](structured_logging.md)
+    - [User Authentication](usage/configuration/user_authentication/README.md)
+      - [Single-Sign On]()
+        - [OpenID Connect](openid.md)
+        - [SAML]()
+        - [CAS]()
+        - [SSO Mapping Providers](sso_mapping_providers.md)
+      - [Password Auth Providers](password_auth_providers.md)
+      - [JSON Web Tokens](jwt.md)
+    - [Registration Captcha](CAPTCHA_SETUP.md)
+    - [Application Services](application_services.md)
+    - [Server Notices](server_notices.md)
+    - [Consent Tracking](consent_tracking.md)
+    - [URL Previews](url_previews.md)
+    - [User Directory](user_directory.md)
+    - [Message Retention Policies](message_retention_policies.md)
+    - [Pluggable Modules]()
+      - [Third Party Rules]()
+      - [Spam Checker](spam_checker.md)
+      - [Presence Router](presence_router_module.md)
+      - [Media Storage Providers]()
+    - [Workers](workers.md)
+      - [Using `synctl` with Workers](synctl_workers.md)
+      - [Systemd](systemd-with-workers/README.md)
+  - [Administration](usage/administration/README.md)
+    - [Admin API](usage/administration/admin_api/README.md)
+      - [Account Validity](admin_api/account_validity.md)
+      - [Delete Group](admin_api/delete_group.md)
+      - [Event Reports](admin_api/event_reports.md)
+      - [Media](admin_api/media_admin_api.md)
+      - [Purge History](admin_api/purge_history_api.md)
+      - [Purge Rooms](admin_api/purge_room.md)
+      - [Register Users](admin_api/register_api.md)
+      - [Manipulate Room Membership](admin_api/room_membership.md)
+      - [Rooms](admin_api/rooms.md)
+      - [Server Notices](admin_api/server_notices.md)
+      - [Shutdown Room](admin_api/shutdown_room.md)
+      - [Statistics](admin_api/statistics.md)
+      - [Users](admin_api/user_admin_api.md)
+      - [Server Version](admin_api/version_api.md)
+    - [Manhole](manhole.md)
+    - [Monitoring](metrics-howto.md)
+    - [Scripts]()
+
+# Development
+  - [Contributing Guide](development/contributing_guide.md)
+  - [Code Style](code_style.md)
+  - [Git Usage](dev/git.md)
+  - [Testing]()
+  - [OpenTracing](opentracing.md)
+  - [Synapse Architecture]()
+    - [Log Contexts](log_contexts.md)
+    - [Replication](replication.md)
+    - [TCP Replication](tcp_replication.md)
+  - [Internal Documentation](development/internal_documentation/README.md)
+    - [Single Sign-On]()
+      - [SAML](dev/saml.md)
+      - [CAS](dev/cas.md)
+    - [State Resolution]()
+      - [The Auth Chain Difference Algorithm](auth_chain_difference_algorithm.md)
+    - [Media Repository](media_repository.md)
+    - [Room and User Statistics](room_and_user_statistics.md)
+  - [Scripts]()
+
+# Other
+  - [Dependency Deprecation Policy](deprecation_policy.md)
\ No newline at end of file
diff --git a/docs/admin_api/README.rst b/docs/admin_api/README.rst
index 9587bee0ce..37cee87d32 100644
--- a/docs/admin_api/README.rst
+++ b/docs/admin_api/README.rst
@@ -1,28 +1,14 @@
 Admin APIs
 ==========
 
-This directory includes documentation for the various synapse specific admin
-APIs available.
-
-Authenticating as a server admin
---------------------------------
-
-Many of the API calls in the admin api will require an `access_token` for a
-server admin. (Note that a server admin is distinct from a room admin.)
-
-A user can be marked as a server admin by updating the database directly, e.g.:
-
-.. code-block:: sql
+**Note**: The latest documentation can be viewed `here <https://matrix-org.github.io/synapse>`_.
+See `docs/README.md <../docs/README.md>`_ for more information.
 
-    UPDATE users SET admin = 1 WHERE name = '@foo:bar.com';
+**Please update links to point to the website instead.** Existing files in this directory
+are preserved to maintain historical links, but may be moved in the future.
 
-A new server admin user can also be created using the
-``register_new_matrix_user`` script.
-
-Finding your user's `access_token` is client-dependent, but will usually be shown in the client's settings.
-
-Once you have your `access_token`, to include it in a request, the best option is to add the token to a request header:
-
-``curl --header "Authorization: Bearer <access_token>" <the_rest_of_your_API_request>``
+This directory includes documentation for the various synapse specific admin
+APIs available. Updates to the existing Admin API documentation should still
+be made to these files, but any new documentation files should instead be placed under
+`docs/usage/administration/admin_api <../docs/usage/administration/admin_api>`_.
 
-Fore more details, please refer to the complete `matrix spec documentation <https://matrix.org/docs/spec/client_server/r0.5.0#using-access-tokens>`_.
diff --git a/docs/admin_api/delete_group.md b/docs/admin_api/delete_group.md
index c061678e75..9c335ff759 100644
--- a/docs/admin_api/delete_group.md
+++ b/docs/admin_api/delete_group.md
@@ -11,4 +11,4 @@ POST /_synapse/admin/v1/delete_group/<group_id>
 ```
 
 To use it, you will need to authenticate by providing an `access_token` for a
-server admin: see [README.rst](README.rst).
+server admin: see [Admin API](../../usage/administration/admin_api).
diff --git a/docs/admin_api/event_reports.md b/docs/admin_api/event_reports.md
index bfec06f755..186139185e 100644
--- a/docs/admin_api/event_reports.md
+++ b/docs/admin_api/event_reports.md
@@ -7,7 +7,7 @@ The api is:
 GET /_synapse/admin/v1/event_reports?from=0&limit=10
 ```
 To use it, you will need to authenticate by providing an `access_token` for a
-server admin: see [README.rst](README.rst).
+server admin: see [Admin API](../../usage/administration/admin_api).
 
 It returns a JSON body like the following:
 
@@ -95,7 +95,7 @@ The api is:
 GET /_synapse/admin/v1/event_reports/<report_id>
 ```
 To use it, you will need to authenticate by providing an `access_token` for a
-server admin: see [README.rst](README.rst).
+server admin: see [Admin API](../../usage/administration/admin_api).
 
 It returns a JSON body like the following:
 
diff --git a/docs/admin_api/media_admin_api.md b/docs/admin_api/media_admin_api.md
index 7709f3d8c7..9ab5269881 100644
--- a/docs/admin_api/media_admin_api.md
+++ b/docs/admin_api/media_admin_api.md
@@ -28,7 +28,7 @@ The API is:
 GET /_synapse/admin/v1/room/<room_id>/media
 ```
 To use it, you will need to authenticate by providing an `access_token` for a
-server admin: see [README.rst](README.rst).
+server admin: see [Admin API](../../usage/administration/admin_api).
 
 The API returns a JSON body like the following:
 ```json
@@ -311,7 +311,7 @@ The following fields are returned in the JSON response body:
 * `deleted`: integer - The number of media items successfully deleted
 
 To use it, you will need to authenticate by providing an `access_token` for a
-server admin: see [README.rst](README.rst).
+server admin: see [Admin API](../../usage/administration/admin_api).
 
 If the user re-requests purged remote media, synapse will re-request the media
 from the originating server.
diff --git a/docs/admin_api/purge_history_api.md b/docs/admin_api/purge_history_api.md
index 44971acd91..25decc3e61 100644
--- a/docs/admin_api/purge_history_api.md
+++ b/docs/admin_api/purge_history_api.md
@@ -17,7 +17,7 @@ POST /_synapse/admin/v1/purge_history/<room_id>[/<event_id>]
 ```
 
 To use it, you will need to authenticate by providing an `access_token` for a
-server admin: [Admin API](README.rst)
+server admin: [Admin API](../../usage/administration/admin_api)
 
 By default, events sent by local users are not deleted, as they may represent
 the only copies of this content in existence. (Events sent by remote users are
diff --git a/docs/admin_api/room_membership.md b/docs/admin_api/room_membership.md
index b6746ff5e4..ed40366099 100644
--- a/docs/admin_api/room_membership.md
+++ b/docs/admin_api/room_membership.md
@@ -24,7 +24,7 @@ POST /_synapse/admin/v1/join/<room_id_or_alias>
 ```
 
 To use it, you will need to authenticate by providing an `access_token` for a
-server admin: see [README.rst](README.rst).
+server admin: see [Admin API](../../usage/administration/admin_api).
 
 Response:
 
diff --git a/docs/admin_api/rooms.md b/docs/admin_api/rooms.md
index 5721210fee..dc007fa00e 100644
--- a/docs/admin_api/rooms.md
+++ b/docs/admin_api/rooms.md
@@ -443,7 +443,7 @@ with a body of:
 ```
 
 To use it, you will need to authenticate by providing an ``access_token`` for a
-server admin: see [README.rst](README.rst).
+server admin: see [Admin API](../../usage/administration/admin_api).
 
 A response body like the following is returned:
 
diff --git a/docs/admin_api/statistics.md b/docs/admin_api/statistics.md
index d398a120fb..d93d52a3ac 100644
--- a/docs/admin_api/statistics.md
+++ b/docs/admin_api/statistics.md
@@ -10,7 +10,7 @@ GET /_synapse/admin/v1/statistics/users/media
 ```
 
 To use it, you will need to authenticate by providing an `access_token`
-for a server admin: see [README.rst](README.rst).
+for a server admin: see [Admin API](../../usage/administration/admin_api).
 
 A response body like the following is returned:
 
diff --git a/docs/admin_api/user_admin_api.md b/docs/admin_api/user_admin_api.md
index 0c843316c9..c835e4a0cd 100644
--- a/docs/admin_api/user_admin_api.md
+++ b/docs/admin_api/user_admin_api.md
@@ -11,7 +11,7 @@ GET /_synapse/admin/v2/users/<user_id>
 ```
 
 To use it, you will need to authenticate by providing an `access_token` for a
-server admin: [Admin API](README.rst)
+server admin: [Admin API](../../usage/administration/admin_api)
 
 It returns a JSON body like the following:
 
@@ -78,7 +78,7 @@ with a body of:
 ```
 
 To use it, you will need to authenticate by providing an `access_token` for a
-server admin: [Admin API](README.rst)
+server admin: [Admin API](../../usage/administration/admin_api)
 
 URL parameters:
 
@@ -119,7 +119,7 @@ GET /_synapse/admin/v2/users?from=0&limit=10&guests=false
 ```
 
 To use it, you will need to authenticate by providing an `access_token` for a
-server admin: [Admin API](README.rst)
+server admin: [Admin API](../../usage/administration/admin_api)
 
 A response body like the following is returned:
 
@@ -237,7 +237,7 @@ See also: [Client Server
 API Whois](https://matrix.org/docs/spec/client_server/r0.6.1#get-matrix-client-r0-admin-whois-userid).
 
 To use it, you will need to authenticate by providing an `access_token` for a
-server admin: [Admin API](README.rst)
+server admin: [Admin API](../../usage/administration/admin_api)
 
 It returns a JSON body like the following:
 
@@ -294,7 +294,7 @@ with a body of:
 ```
 
 To use it, you will need to authenticate by providing an `access_token` for a
-server admin: [Admin API](README.rst)
+server admin: [Admin API](../../usage/administration/admin_api)
 
 The erase parameter is optional and defaults to `false`.
 An empty body may be passed for backwards compatibility.
@@ -339,7 +339,7 @@ with a body of:
 ```
 
 To use it, you will need to authenticate by providing an `access_token` for a
-server admin: [Admin API](README.rst)
+server admin: [Admin API](../../usage/administration/admin_api)
 
 The parameter `new_password` is required.
 The parameter `logout_devices` is optional and defaults to `true`.
@@ -354,7 +354,7 @@ GET /_synapse/admin/v1/users/<user_id>/admin
 ```
 
 To use it, you will need to authenticate by providing an `access_token` for a
-server admin: [Admin API](README.rst)
+server admin: [Admin API](../../usage/administration/admin_api)
 
 A response body like the following is returned:
 
@@ -384,7 +384,7 @@ with a body of:
 ```
 
 To use it, you will need to authenticate by providing an `access_token` for a
-server admin: [Admin API](README.rst)
+server admin: [Admin API](../../usage/administration/admin_api)
 
 
 ## List room memberships of a user
@@ -398,7 +398,7 @@ GET /_synapse/admin/v1/users/<user_id>/joined_rooms
 ```
 
 To use it, you will need to authenticate by providing an `access_token` for a
-server admin: [Admin API](README.rst)
+server admin: [Admin API](../../usage/administration/admin_api)
 
 A response body like the following is returned:
 
@@ -443,7 +443,7 @@ GET /_synapse/admin/v1/users/<user_id>/media
 ```
 
 To use it, you will need to authenticate by providing an `access_token` for a
-server admin: [Admin API](README.rst)
+server admin: [Admin API](../../usage/administration/admin_api)
 
 A response body like the following is returned:
 
@@ -591,7 +591,7 @@ GET /_synapse/admin/v2/users/<user_id>/devices
 ```
 
 To use it, you will need to authenticate by providing an `access_token` for a
-server admin: [Admin API](README.rst)
+server admin: [Admin API](../../usage/administration/admin_api)
 
 A response body like the following is returned:
 
@@ -659,7 +659,7 @@ POST /_synapse/admin/v2/users/<user_id>/delete_devices
 ```
 
 To use it, you will need to authenticate by providing an `access_token` for a
-server admin: [Admin API](README.rst)
+server admin: [Admin API](../../usage/administration/admin_api)
 
 An empty JSON dict is returned.
 
@@ -683,7 +683,7 @@ GET /_synapse/admin/v2/users/<user_id>/devices/<device_id>
 ```
 
 To use it, you will need to authenticate by providing an `access_token` for a
-server admin: [Admin API](README.rst)
+server admin: [Admin API](../../usage/administration/admin_api)
 
 A response body like the following is returned:
 
@@ -731,7 +731,7 @@ PUT /_synapse/admin/v2/users/<user_id>/devices/<device_id>
 ```
 
 To use it, you will need to authenticate by providing an `access_token` for a
-server admin: [Admin API](README.rst)
+server admin: [Admin API](../../usage/administration/admin_api)
 
 An empty JSON dict is returned.
 
@@ -760,7 +760,7 @@ DELETE /_synapse/admin/v2/users/<user_id>/devices/<device_id>
 ```
 
 To use it, you will need to authenticate by providing an `access_token` for a
-server admin: [Admin API](README.rst)
+server admin: [Admin API](../../usage/administration/admin_api)
 
 An empty JSON dict is returned.
 
@@ -781,7 +781,7 @@ GET /_synapse/admin/v1/users/<user_id>/pushers
 ```
 
 To use it, you will need to authenticate by providing an `access_token` for a
-server admin: [Admin API](README.rst)
+server admin: [Admin API](../../usage/administration/admin_api)
 
 A response body like the following is returned:
 
@@ -872,7 +872,7 @@ POST /_synapse/admin/v1/users/<user_id>/shadow_ban
 ```
 
 To use it, you will need to authenticate by providing an `access_token` for a
-server admin: [Admin API](README.rst)
+server admin: [Admin API](../../usage/administration/admin_api)
 
 An empty JSON dict is returned.
 
@@ -897,7 +897,7 @@ GET /_synapse/admin/v1/users/<user_id>/override_ratelimit
 ```
 
 To use it, you will need to authenticate by providing an `access_token` for a
-server admin: [Admin API](README.rst)
+server admin: [Admin API](../../usage/administration/admin_api)
 
 A response body like the following is returned:
 
@@ -939,7 +939,7 @@ POST /_synapse/admin/v1/users/<user_id>/override_ratelimit
 ```
 
 To use it, you will need to authenticate by providing an `access_token` for a
-server admin: [Admin API](README.rst)
+server admin: [Admin API](../../usage/administration/admin_api)
 
 A response body like the following is returned:
 
@@ -984,7 +984,7 @@ DELETE /_synapse/admin/v1/users/<user_id>/override_ratelimit
 ```
 
 To use it, you will need to authenticate by providing an `access_token` for a
-server admin: [Admin API](README.rst)
+server admin: [Admin API](../../usage/administration/admin_api)
 
 An empty JSON dict is returned.
 
diff --git a/docs/development/contributing_guide.md b/docs/development/contributing_guide.md
new file mode 100644
index 0000000000..ddf0887123
--- /dev/null
+++ b/docs/development/contributing_guide.md
@@ -0,0 +1,7 @@
+<!--
+  Include the contents of CONTRIBUTING.md from the project root (where GitHub likes it 
+  to be)
+-->
+# Contributing
+
+{{#include ../../CONTRIBUTING.md}}
diff --git a/docs/development/internal_documentation/README.md b/docs/development/internal_documentation/README.md
new file mode 100644
index 0000000000..51c5fb94d5
--- /dev/null
+++ b/docs/development/internal_documentation/README.md
@@ -0,0 +1,12 @@
+# Internal Documentation
+
+This section covers implementation documentation for various parts of Synapse.
+
+If a developer is planning to make a change to a feature of Synapse, it can be useful for
+general documentation of how that feature is implemented to be available. This saves the
+developer time in place of needing to understand how the feature works by reading the
+code.
+
+Documentation that would be more useful for the perspective of a system administrator,
+rather than a developer who's intending to change to code, should instead be placed
+under the Usage section of the documentation.
\ No newline at end of file
diff --git a/docs/favicon.png b/docs/favicon.png
new file mode 100644
index 0000000000..5f18bf641f
--- /dev/null
+++ b/docs/favicon.png
Binary files differdiff --git a/docs/favicon.svg b/docs/favicon.svg
new file mode 100644
index 0000000000..e571aeb3ed
--- /dev/null
+++ b/docs/favicon.svg
@@ -0,0 +1,58 @@
+<?xml version="1.0" encoding="UTF-8" standalone="no"?>
+<svg
+   xmlns:dc="http://purl.org/dc/elements/1.1/"
+   xmlns:cc="http://creativecommons.org/ns#"
+   xmlns:rdf="http://www.w3.org/1999/02/22-rdf-syntax-ns#"
+   xmlns:svg="http://www.w3.org/2000/svg"
+   xmlns="http://www.w3.org/2000/svg"
+   xmlns:sodipodi="http://sodipodi.sourceforge.net/DTD/sodipodi-0.dtd"
+   xmlns:inkscape="http://www.inkscape.org/namespaces/inkscape"
+   viewBox="0 0 199.7 184.2"
+   version="1.1"
+   id="svg62"
+   sodipodi:docname="mdbook-favicon.svg"
+   inkscape:version="1.0.2 (e86c870879, 2021-01-15, custom)">
+  <metadata
+     id="metadata68">
+    <rdf:RDF>
+      <cc:Work
+         rdf:about="">
+        <dc:format>image/svg+xml</dc:format>
+        <dc:type
+           rdf:resource="http://purl.org/dc/dcmitype/StillImage" />
+      </cc:Work>
+    </rdf:RDF>
+  </metadata>
+  <defs
+     id="defs66" />
+  <sodipodi:namedview
+     pagecolor="#ffffff"
+     bordercolor="#666666"
+     borderopacity="1"
+     objecttolerance="10"
+     gridtolerance="10"
+     guidetolerance="10"
+     inkscape:pageopacity="0"
+     inkscape:pageshadow="2"
+     inkscape:window-width="1920"
+     inkscape:window-height="1026"
+     id="namedview64"
+     showgrid="false"
+     inkscape:zoom="3.2245912"
+     inkscape:cx="84.790185"
+     inkscape:cy="117.96478"
+     inkscape:window-x="0"
+     inkscape:window-y="0"
+     inkscape:window-maximized="1"
+     inkscape:current-layer="svg62" />
+  <style
+     id="style58">
+    @media (prefers-color-scheme: dark) {
+      svg { fill: white; }
+    }
+  </style>
+  <path
+     d="m 189.5,36.8 c 0.2,2.8 0,5.1 -0.6,6.8 L 153,162 c -0.6,2.1 -2,3.7 -4.2,5 -2.2,1.2 -4.4,1.9 -6.7,1.9 H 31.4 c -9.6,0 -15.3,-2.8 -17.3,-8.4 -0.8,-2.2 -0.8,-3.9 0.1,-5.2 0.9,-1.2 2.4,-1.8 4.6,-1.8 H 123 c 7.4,0 12.6,-1.4 15.4,-4.1 2.8,-2.7 5.7,-8.9 8.6,-18.4 L 179.9,22.4 c 1.8,-5.9 1,-11.1 -2.2,-15.6 C 174.5,2.3 169.9,0 164,0 H 72.7 c -1,0 -3.1,0.4 -6.1,1.1 L 66.7,0.7 C 64.5,0.2 62.6,0 61,0.1 c -1.6,0.1 -3,0.5 -4.3,1.4 -1.3,0.9 -2.4,1.8 -3.2,2.8 -0.8,1 -1.5,2.2 -2.3,3.8 -0.8,1.6 -1.4,3 -1.9,4.3 -0.5,1.3 -1.1,2.7 -1.8,4.2 -0.7,1.5 -1.3,2.7 -2,3.7 -0.5,0.6 -1.2,1.5 -2,2.5 -0.8,1 -1.6,2 -2.2,2.8 -0.6,0.8 -0.9,1.5 -1.1,2.2 -0.2,0.7 -0.1,1.8 0.2,3.2 0.3,1.4 0.4,2.4 0.4,3.1 -0.3,3 -1.4,6.9 -3.3,11.6 -1.9,4.7 -3.6,8.1 -5.1,10.1 -0.3,0.4 -1.2,1.3 -2.6,2.7 -1.4,1.4 -2.3,2.6 -2.6,3.7 -0.3,0.4 -0.3,1.5 -0.1,3.4 0.3,1.8 0.4,3.1 0.3,3.8 -0.3,2.7 -1.3,6.3 -3,10.8 -2.406801,6.370944 -3.4,8.2 -5,11 -0.2,0.5 -0.9,1.4 -2,2.8 -1.1,1.4 -1.8,2.5 -2,3.4 -0.2,0.6 -0.1,1.8 0.1,3.4 0.2,1.6 0.2,2.8 -0.1,3.6 -0.6,3 -1.8,6.7 -3.6,11 -1.8,4.3 -3.6,7.9 -5.4,11 -0.5,0.8 -1.1,1.7 -2,2.8 -0.8,1.1 -1.5,2 -2,2.8 -0.5,0.8 -0.8,1.6 -1,2.5 -0.1,0.5 0,1.3 0.4,2.3 0.3,1.1 0.4,1.9 0.4,2.6 -0.1,1.1 -0.2,2.6 -0.5,4.4 -0.2,1.8 -0.4,2.9 -0.4,3.2 -1.8,4.8 -1.7,9.9 0.2,15.2 2.2,6.2 6.2,11.5 11.9,15.8 5.7,4.3 11.7,6.4 17.8,6.4 h 110.7 c 5.2,0 10.1,-1.7 14.7,-5.2 4.6,-3.5 7.7,-7.8 9.2,-12.9 l 33,-108.6 c 1.8,-5.8 1,-10.9 -2.2,-15.5 -1.7,-2.5 -4,-4.2 -7.1,-5.4 z M 38.14858,105.59813 60.882735,41.992545 h 10.8 c 6.340631,0 33.351895,0.778957 70.804135,0.970479 -18.18245,63.254766 0,0 -18.18245,63.254766 -23.00947,-0.10382 -63.362955,-0.6218 -72.55584,-0.51966 -18,0.2 -13.6,-0.1 -13.6,-0.1 z m 80.621,-5.891206 c 15.19043,-50.034423 0,1e-5 15.19043,-50.034423 l -11.90624,-0.13228 2.73304,-9.302941 -44.32863,0.07339 -2.532953,8.036036 -11.321128,-0.18864 -17.955519,51.440073 c 0.02698,0.027 4.954586,0.0514 12.187488,0.0717 l -2.997994,9.804886 c 11.36463,0.0271 1.219679,-0.0736 46.117666,-0.31499 l 2.65246,-9.571696 c 7.08021,0.14819 11.59705,0.13117 12.16138,0.1189 z m -56.149615,-3.855606 13.7,-42.5 h 9.8 l 1.194896,32.99936 23.205109,-32.99936 h 9.9 l -13.6,42.5 h -7.099996 l 12.499996,-35.4 -24.50001,35.4 h -6.799995 l -0.8,-35 -10.8,35 z"
+     id="path60"
+     sodipodi:nodetypes="ccccssccsssccsssccsssssscsssscssscccscscscsccsccccccssssccccccsccsccccccccccccccccccccccccccccc" />
+</svg>
diff --git a/docs/setup/installation.md b/docs/setup/installation.md
new file mode 100644
index 0000000000..8bb1cffd3d
--- /dev/null
+++ b/docs/setup/installation.md
@@ -0,0 +1,7 @@
+<!--
+  Include the contents of INSTALL.md from the project root without moving it, which may
+  break links around the internet. Additionally, note that SUMMARY.md is unable to 
+  directly link to content outside of the docs/ directory. So we use this file as a 
+  redirection.
+-->
+{{#include ../../INSTALL.md}}
\ No newline at end of file
diff --git a/docs/upgrading/README.md b/docs/upgrading/README.md
new file mode 100644
index 0000000000..258e58cf15
--- /dev/null
+++ b/docs/upgrading/README.md
@@ -0,0 +1,7 @@
+<!--
+  Include the contents of UPGRADE.rst from the project root without moving it, which may
+  break links around the internet. Additionally, note that SUMMARY.md is unable to 
+  directly link to content outside of the docs/ directory. So we use this file as a 
+  redirection.
+-->
+{{#include ../../UPGRADE.rst}}
\ No newline at end of file
diff --git a/docs/usage/administration/README.md b/docs/usage/administration/README.md
new file mode 100644
index 0000000000..e1e57546ab
--- /dev/null
+++ b/docs/usage/administration/README.md
@@ -0,0 +1,7 @@
+# Administration
+
+This section contains information on managing your Synapse homeserver. This includes:
+
+* Managing users, rooms and media via the Admin API.
+* Setting up metrics and monitoring to give you insight into your homeserver's health.
+* Configuring structured logging.
\ No newline at end of file
diff --git a/docs/usage/administration/admin_api/README.md b/docs/usage/administration/admin_api/README.md
new file mode 100644
index 0000000000..2fca96f8be
--- /dev/null
+++ b/docs/usage/administration/admin_api/README.md
@@ -0,0 +1,29 @@
+# The Admin API
+
+## Authenticate as a server admin
+
+Many of the API calls in the admin api will require an `access_token` for a
+server admin. (Note that a server admin is distinct from a room admin.)
+
+A user can be marked as a server admin by updating the database directly, e.g.:
+
+```sql
+UPDATE users SET admin = 1 WHERE name = '@foo:bar.com';
+```
+
+A new server admin user can also be created using the `register_new_matrix_user`
+command. This is a script that is located in the `scripts/` directory, or possibly
+already on your `$PATH` depending on how Synapse was installed.
+
+Finding your user's `access_token` is client-dependent, but will usually be shown in the client's settings.
+
+## Making an Admin API request
+Once you have your `access_token`, you will need to authenticate each request to an Admin API endpoint by
+providing the token as either a query parameter or a request header. To add it as a request header in cURL:
+
+```sh
+curl --header "Authorization: Bearer <access_token>" <the_rest_of_your_API_request>
+```
+
+For more details on access tokens in Matrix, please refer to the complete
+[matrix spec documentation](https://matrix.org/docs/spec/client_server/r0.6.1#using-access-tokens).
diff --git a/docs/usage/configuration/README.md b/docs/usage/configuration/README.md
new file mode 100644
index 0000000000..41d41167c6
--- /dev/null
+++ b/docs/usage/configuration/README.md
@@ -0,0 +1,4 @@
+# Configuration
+
+This section contains information on tweaking Synapse via the various options in the configuration file. A configuration
+file should have been generated when you [installed Synapse](../../setup/installation.html).
diff --git a/docs/usage/configuration/homeserver_sample_config.md b/docs/usage/configuration/homeserver_sample_config.md
new file mode 100644
index 0000000000..11e806998d
--- /dev/null
+++ b/docs/usage/configuration/homeserver_sample_config.md
@@ -0,0 +1,14 @@
+# Homeserver Sample Configuration File
+
+Below is a sample homeserver configuration file. The homeserver configuration file 
+can be tweaked to change the behaviour of your homeserver. A restart of the server is 
+generally required to apply any changes made to this file.
+
+Note that the contents below are *not* intended to be copied and used as the basis for
+a real homeserver.yaml. Instead, if you are starting from scratch, please generate
+a fresh config using Synapse by following the instructions in
+[Installation](../../setup/installation.md).
+
+```yaml
+{{#include ../../sample_config.yaml}}
+```
diff --git a/docs/usage/configuration/logging_sample_config.md b/docs/usage/configuration/logging_sample_config.md
new file mode 100644
index 0000000000..4c4bc6fc16
--- /dev/null
+++ b/docs/usage/configuration/logging_sample_config.md
@@ -0,0 +1,14 @@
+# Logging Sample Configuration File
+
+Below is a sample logging configuration file. This file can be tweaked to control how your
+homeserver will output logs. A restart of the server is generally required to apply any
+changes made to this file.
+
+Note that the contents below are *not* intended to be copied and used as the basis for
+a real homeserver.yaml. Instead, if you are starting from scratch, please generate
+a fresh config using Synapse by following the instructions in
+[Installation](../../setup/installation.md).
+
+```yaml
+{{#include ../../sample_log_config.yaml}}
+``__`
\ No newline at end of file
diff --git a/docs/usage/configuration/user_authentication/README.md b/docs/usage/configuration/user_authentication/README.md
new file mode 100644
index 0000000000..087ae053cf
--- /dev/null
+++ b/docs/usage/configuration/user_authentication/README.md
@@ -0,0 +1,15 @@
+# User Authentication
+
+Synapse supports multiple methods of authenticating users, either out-of-the-box or through custom pluggable
+authentication modules.
+
+Included in Synapse is support for authenticating users via:
+
+* A username and password.
+* An email address and password.
+* Single Sign-On through the SAML, Open ID Connect or CAS protocols.
+* JSON Web Tokens.
+* An administrator's shared secret.
+
+Synapse can additionally be extended to support custom authentication schemes through optional "password auth provider"
+modules.
\ No newline at end of file
diff --git a/docs/website_files/README.md b/docs/website_files/README.md
new file mode 100644
index 0000000000..04d191479b
--- /dev/null
+++ b/docs/website_files/README.md
@@ -0,0 +1,30 @@
+# Documentation Website Files and Assets
+
+This directory contains extra files for modifying the look and functionality of 
+[mdbook](https://github.com/rust-lang/mdBook), the documentation software that's
+used to generate Synapse's documentation website.
+
+The configuration options in the `output.html` section of [book.toml](../../book.toml)
+point to additional JS/CSS in this directory that are added on each page load. In
+addition, the `theme` directory contains files that overwrite their counterparts in
+each of the default themes included with mdbook.
+
+Currently we use these files to generate a floating Table of Contents panel. The code for
+which was partially taken from
+[JorelAli/mdBook-pagetoc](https://github.com/JorelAli/mdBook-pagetoc/)
+before being modified such that it scrolls with the content of the page. This is handled
+by the `table-of-contents.js/css` files. The table of contents panel only appears on pages
+that have more than one header, as well as only appearing on desktop-sized monitors.
+
+We remove the navigation arrows which typically appear on the left and right side of the
+screen on desktop as they interfere with the table of contents. This is handled by
+the `remove-nav-buttons.css` file.
+
+Finally, we also stylise the chapter titles in the left sidebar by indenting them
+slightly so that they are more visually distinguishable from the section headers
+(the bold titles). This is done through the `indent-section-headers.css` file.
+
+More information can be found in mdbook's official documentation for
+[injecting page JS/CSS](https://rust-lang.github.io/mdBook/format/config.html)
+and
+[customising the default themes](https://rust-lang.github.io/mdBook/format/theme/index.html).
\ No newline at end of file
diff --git a/docs/website_files/indent-section-headers.css b/docs/website_files/indent-section-headers.css
new file mode 100644
index 0000000000..f9b3c82ca6
--- /dev/null
+++ b/docs/website_files/indent-section-headers.css
@@ -0,0 +1,7 @@
+/*
+ * Indents each chapter title in the left sidebar so that they aren't
+ * at the same level as the section headers.
+ */
+.chapter-item {
+    margin-left: 1em;
+}
\ No newline at end of file
diff --git a/docs/website_files/remove-nav-buttons.css b/docs/website_files/remove-nav-buttons.css
new file mode 100644
index 0000000000..4b280794ea
--- /dev/null
+++ b/docs/website_files/remove-nav-buttons.css
@@ -0,0 +1,8 @@
+/* Remove the prev, next chapter buttons as they interfere with the
+ * table of contents.
+ * Note that the table of contents only appears on desktop, thus we
+ * only remove the desktop (wide) chapter buttons.
+ */
+.nav-wide-wrapper {
+    display: none
+}
\ No newline at end of file
diff --git a/docs/website_files/table-of-contents.css b/docs/website_files/table-of-contents.css
new file mode 100644
index 0000000000..d16bb3b988
--- /dev/null
+++ b/docs/website_files/table-of-contents.css
@@ -0,0 +1,42 @@
+@media only screen and (max-width:1439px) {
+    .sidetoc {
+        display: none;
+    }
+}
+
+@media only screen and (min-width:1440px) {
+    main {
+        position: relative;
+        margin-left: 100px !important;
+    }
+    .sidetoc {
+        margin-left: auto;
+        margin-right: auto;
+        left: calc(100% + (var(--content-max-width))/4 - 140px);
+        position: absolute;
+        text-align: right;
+    }
+    .pagetoc {
+        position: fixed;
+        width: 250px;
+        overflow: auto;
+        right: 20px;
+        height: calc(100% - var(--menu-bar-height));
+    }
+    .pagetoc a {
+        color: var(--fg) !important;
+        display: block;
+        padding: 5px 15px 5px 10px;
+        text-align: left;
+        text-decoration: none;
+    }
+    .pagetoc a:hover,
+    .pagetoc a.active {
+        background: var(--sidebar-bg) !important;
+        color: var(--sidebar-fg) !important;
+    }
+    .pagetoc .active {
+        background: var(--sidebar-bg);
+        color: var(--sidebar-fg);
+    }
+}
diff --git a/docs/website_files/table-of-contents.js b/docs/website_files/table-of-contents.js
new file mode 100644
index 0000000000..0de5960b22
--- /dev/null
+++ b/docs/website_files/table-of-contents.js
@@ -0,0 +1,134 @@
+const getPageToc = () => document.getElementsByClassName('pagetoc')[0];
+
+const pageToc = getPageToc();
+const pageTocChildren = [...pageToc.children];
+const headers = [...document.getElementsByClassName('header')];
+
+
+// Select highlighted item in ToC when clicking an item
+pageTocChildren.forEach(child => {
+    child.addEventHandler('click', () => {
+        pageTocChildren.forEach(child => {
+            child.classList.remove('active');
+        });
+        child.classList.add('active');
+    });
+});
+
+
+/**
+ * Test whether a node is in the viewport
+ */
+function isInViewport(node) {
+    const rect = node.getBoundingClientRect();
+    return rect.top >= 0 && rect.left >= 0 && rect.bottom <= (window.innerHeight || document.documentElement.clientHeight) && rect.right <= (window.innerWidth || document.documentElement.clientWidth);
+}
+
+
+/**
+ * Set a new ToC entry.
+ * Clear any previously highlighted ToC items, set the new one,
+ * and adjust the ToC scroll position.
+ */
+function setTocEntry() {
+    let activeEntry;
+    const pageTocChildren = [...getPageToc().children];
+
+    // Calculate which header is the current one at the top of screen
+    headers.forEach(header => {
+        if (window.pageYOffset >= header.offsetTop) {
+            activeEntry = header;
+        }
+    });
+
+    // Update selected item in ToC when scrolling
+    pageTocChildren.forEach(child => {
+        if (activeEntry.href.localeCompare(child.href) === 0) {
+            child.classList.add('active');
+        } else {
+            child.classList.remove('active');
+        }
+    });
+
+    let tocEntryForLocation = document.querySelector(`nav a[href="${activeEntry.href}"]`);
+    if (tocEntryForLocation) {
+        const headingForLocation = document.querySelector(activeEntry.hash);
+        if (headingForLocation && isInViewport(headingForLocation)) {
+            // Update ToC scroll
+            const nav = getPageToc();
+            const content = document.querySelector('html');
+            if (content.scrollTop !== 0) {
+                nav.scrollTo({
+                    top: tocEntryForLocation.offsetTop - 100,
+                    left: 0,
+                    behavior: 'smooth',
+                });
+            } else {
+                nav.scrollTop = 0;
+            }
+        }
+    }
+}
+
+
+/**
+ * Populate sidebar on load
+ */
+window.addEventListener('load', () => {
+    // Only create table of contents if there is more than one header on the page
+    if (headers.length <= 1) {
+        return;
+    }
+
+    // Create an entry in the page table of contents for each header in the document
+    headers.forEach((header, index) => {
+        const link = document.createElement('a');
+
+        // Indent shows hierarchy
+        let indent = '0px';
+        switch (header.parentElement.tagName) {
+            case 'H1':
+                indent = '5px';
+                break;
+            case 'H2':
+                indent = '20px';
+                break;
+            case 'H3':
+                indent = '30px';
+                break;
+            case 'H4':
+                indent = '40px';
+                break;
+            case 'H5':
+                indent = '50px';
+                break;
+            case 'H6':
+                indent = '60px';
+                break;
+            default:
+                break;
+        }
+
+        let tocEntry;
+        if (index == 0) {
+            // Create a bolded title for the first element
+            tocEntry = document.createElement("strong");
+            tocEntry.innerHTML = header.text;
+        } else {
+            // All other elements are non-bold
+            tocEntry = document.createTextNode(header.text);
+        }
+        link.appendChild(tocEntry);
+
+        link.style.paddingLeft = indent;
+        link.href = header.href;
+        pageToc.appendChild(link);
+    });
+    setTocEntry.call();
+});
+
+
+// Handle active headers on scroll, if there is more than one header on the page
+if (headers.length > 1) {
+    window.addEventListener('scroll', setTocEntry);
+}
diff --git a/docs/website_files/theme/index.hbs b/docs/website_files/theme/index.hbs
new file mode 100644
index 0000000000..3b7a5b6163
--- /dev/null
+++ b/docs/website_files/theme/index.hbs
@@ -0,0 +1,312 @@
+<!DOCTYPE HTML>
+<html lang="{{ language }}" class="sidebar-visible no-js {{ default_theme }}">
+    <head>
+        <!-- Book generated using mdBook -->
+        <meta charset="UTF-8">
+        <title>{{ title }}</title>
+        {{#if is_print }}
+        <meta name="robots" content="noindex" />
+        {{/if}}
+        {{#if base_url}}
+        <base href="{{ base_url }}">
+        {{/if}}
+
+
+        <!-- Custom HTML head -->
+        {{> head}}
+
+        <meta content="text/html; charset=utf-8" http-equiv="Content-Type">
+        <meta name="description" content="{{ description }}">
+        <meta name="viewport" content="width=device-width, initial-scale=1">
+        <meta name="theme-color" content="#ffffff" />
+
+        {{#if favicon_svg}}
+        <link rel="icon" href="{{ path_to_root }}favicon.svg">
+        {{/if}}
+        {{#if favicon_png}}
+        <link rel="shortcut icon" href="{{ path_to_root }}favicon.png">
+        {{/if}}
+        <link rel="stylesheet" href="{{ path_to_root }}css/variables.css">
+        <link rel="stylesheet" href="{{ path_to_root }}css/general.css">
+        <link rel="stylesheet" href="{{ path_to_root }}css/chrome.css">
+        {{#if print_enable}}
+        <link rel="stylesheet" href="{{ path_to_root }}css/print.css" media="print">
+        {{/if}}
+
+        <!-- Fonts -->
+        <link rel="stylesheet" href="{{ path_to_root }}FontAwesome/css/font-awesome.css">
+        {{#if copy_fonts}}
+        <link rel="stylesheet" href="{{ path_to_root }}fonts/fonts.css">
+        {{/if}}
+
+        <!-- Highlight.js Stylesheets -->
+        <link rel="stylesheet" href="{{ path_to_root }}highlight.css">
+        <link rel="stylesheet" href="{{ path_to_root }}tomorrow-night.css">
+        <link rel="stylesheet" href="{{ path_to_root }}ayu-highlight.css">
+
+        <!-- Custom theme stylesheets -->
+        {{#each additional_css}}
+        <link rel="stylesheet" href="{{ ../path_to_root }}{{ this }}">
+        {{/each}}
+
+        {{#if mathjax_support}}
+        <!-- MathJax -->
+        <script async type="text/javascript" src="https://cdnjs.cloudflare.com/ajax/libs/mathjax/2.7.1/MathJax.js?config=TeX-AMS-MML_HTMLorMML"></script>
+        {{/if}}
+    </head>
+    <body>
+        <!-- Provide site root to javascript -->
+        <script type="text/javascript">
+            var path_to_root = "{{ path_to_root }}";
+            var default_theme = window.matchMedia("(prefers-color-scheme: dark)").matches ? "{{ preferred_dark_theme }}" : "{{ default_theme }}";
+        </script>
+
+        <!-- Work around some values being stored in localStorage wrapped in quotes -->
+        <script type="text/javascript">
+            try {
+                var theme = localStorage.getItem('mdbook-theme');
+                var sidebar = localStorage.getItem('mdbook-sidebar');
+                if (theme.startsWith('"') && theme.endsWith('"')) {
+                    localStorage.setItem('mdbook-theme', theme.slice(1, theme.length - 1));
+                }
+                if (sidebar.startsWith('"') && sidebar.endsWith('"')) {
+                    localStorage.setItem('mdbook-sidebar', sidebar.slice(1, sidebar.length - 1));
+                }
+            } catch (e) { }
+        </script>
+
+        <!-- Set the theme before any content is loaded, prevents flash -->
+        <script type="text/javascript">
+            var theme;
+            try { theme = localStorage.getItem('mdbook-theme'); } catch(e) { }
+            if (theme === null || theme === undefined) { theme = default_theme; }
+            var html = document.querySelector('html');
+            html.classList.remove('no-js')
+            html.classList.remove('{{ default_theme }}')
+            html.classList.add(theme);
+            html.classList.add('js');
+        </script>
+
+        <!-- Hide / unhide sidebar before it is displayed -->
+        <script type="text/javascript">
+            var html = document.querySelector('html');
+            var sidebar = 'hidden';
+            if (document.body.clientWidth >= 1080) {
+                try { sidebar = localStorage.getItem('mdbook-sidebar'); } catch(e) { }
+                sidebar = sidebar || 'visible';
+            }
+            html.classList.remove('sidebar-visible');
+            html.classList.add("sidebar-" + sidebar);
+        </script>
+
+        <nav id="sidebar" class="sidebar" aria-label="Table of contents">
+            <div class="sidebar-scrollbox">
+                {{#toc}}{{/toc}}
+            </div>
+            <div id="sidebar-resize-handle" class="sidebar-resize-handle"></div>
+        </nav>
+
+        <div id="page-wrapper" class="page-wrapper">
+
+            <div class="page">
+                {{> header}}
+                <div id="menu-bar-hover-placeholder"></div>
+                <div id="menu-bar" class="menu-bar sticky bordered">
+                    <div class="left-buttons">
+                        <button id="sidebar-toggle" class="icon-button" type="button" title="Toggle Table of Contents" aria-label="Toggle Table of Contents" aria-controls="sidebar">
+                            <i class="fa fa-bars"></i>
+                        </button>
+                        <button id="theme-toggle" class="icon-button" type="button" title="Change theme" aria-label="Change theme" aria-haspopup="true" aria-expanded="false" aria-controls="theme-list">
+                            <i class="fa fa-paint-brush"></i>
+                        </button>
+                        <ul id="theme-list" class="theme-popup" aria-label="Themes" role="menu">
+                            <li role="none"><button role="menuitem" class="theme" id="light">{{ theme_option "Light" }}</button></li>
+                            <li role="none"><button role="menuitem" class="theme" id="rust">{{ theme_option "Rust" }}</button></li>
+                            <li role="none"><button role="menuitem" class="theme" id="coal">{{ theme_option "Coal" }}</button></li>
+                            <li role="none"><button role="menuitem" class="theme" id="navy">{{ theme_option "Navy" }}</button></li>
+                            <li role="none"><button role="menuitem" class="theme" id="ayu">{{ theme_option "Ayu" }}</button></li>
+                        </ul>
+                        {{#if search_enabled}}
+                        <button id="search-toggle" class="icon-button" type="button" title="Search. (Shortkey: s)" aria-label="Toggle Searchbar" aria-expanded="false" aria-keyshortcuts="S" aria-controls="searchbar">
+                            <i class="fa fa-search"></i>
+                        </button>
+                        {{/if}}
+                    </div>
+
+                    <h1 class="menu-title">{{ book_title }}</h1>
+
+                    <div class="right-buttons">
+                        {{#if print_enable}}
+                        <a href="{{ path_to_root }}print.html" title="Print this book" aria-label="Print this book">
+                            <i id="print-button" class="fa fa-print"></i>
+                        </a>
+                        {{/if}}
+                        {{#if git_repository_url}}
+                        <a href="{{git_repository_url}}" title="Git repository" aria-label="Git repository">
+                            <i id="git-repository-button" class="fa {{git_repository_icon}}"></i>
+                        </a>
+                        {{/if}}
+                        {{#if git_repository_edit_url}}
+                        <a href="{{git_repository_edit_url}}" title="Suggest an edit" aria-label="Suggest an edit">
+                            <i id="git-edit-button" class="fa fa-edit"></i>
+                        </a>
+                        {{/if}}
+
+                    </div>
+                </div>
+
+                {{#if search_enabled}}
+                <div id="search-wrapper" class="hidden">
+                    <form id="searchbar-outer" class="searchbar-outer">
+                        <input type="search" id="searchbar" name="searchbar" placeholder="Search this book ..." aria-controls="searchresults-outer" aria-describedby="searchresults-header">
+                    </form>
+                    <div id="searchresults-outer" class="searchresults-outer hidden">
+                        <div id="searchresults-header" class="searchresults-header"></div>
+                        <ul id="searchresults">
+                        </ul>
+                    </div>
+                </div>
+                {{/if}}
+
+                <!-- Apply ARIA attributes after the sidebar and the sidebar toggle button are added to the DOM -->
+                <script type="text/javascript">
+                    document.getElementById('sidebar-toggle').setAttribute('aria-expanded', sidebar === 'visible');
+                    document.getElementById('sidebar').setAttribute('aria-hidden', sidebar !== 'visible');
+                    Array.from(document.querySelectorAll('#sidebar a')).forEach(function(link) {
+                        link.setAttribute('tabIndex', sidebar === 'visible' ? 0 : -1);
+                    });
+                </script>
+
+                <div id="content" class="content">
+                    <main>
+                        <!-- Page table of contents -->
+                        <div class="sidetoc">
+                            <nav class="pagetoc"></nav>
+                        </div>
+
+                        {{{ content }}}
+                    </main>
+
+                    <nav class="nav-wrapper" aria-label="Page navigation">
+                        <!-- Mobile navigation buttons -->
+                        {{#previous}}
+                            <a rel="prev" href="{{ path_to_root }}{{link}}" class="mobile-nav-chapters previous" title="Previous chapter" aria-label="Previous chapter" aria-keyshortcuts="Left">
+                                <i class="fa fa-angle-left"></i>
+                            </a>
+                        {{/previous}}
+
+                        {{#next}}
+                            <a rel="next" href="{{ path_to_root }}{{link}}" class="mobile-nav-chapters next" title="Next chapter" aria-label="Next chapter" aria-keyshortcuts="Right">
+                                <i class="fa fa-angle-right"></i>
+                            </a>
+                        {{/next}}
+
+                        <div style="clear: both"></div>
+                    </nav>
+                </div>
+            </div>
+
+            <nav class="nav-wide-wrapper" aria-label="Page navigation">
+                {{#previous}}
+                    <a rel="prev" href="{{ path_to_root }}{{link}}" class="nav-chapters previous" title="Previous chapter" aria-label="Previous chapter" aria-keyshortcuts="Left">
+                        <i class="fa fa-angle-left"></i>
+                    </a>
+                {{/previous}}
+
+                {{#next}}
+                    <a rel="next" href="{{ path_to_root }}{{link}}" class="nav-chapters next" title="Next chapter" aria-label="Next chapter" aria-keyshortcuts="Right">
+                        <i class="fa fa-angle-right"></i>
+                    </a>
+                {{/next}}
+            </nav>
+
+        </div>
+
+        {{#if livereload}}
+        <!-- Livereload script (if served using the cli tool) -->
+        <script type="text/javascript">
+            var socket = new WebSocket("{{{livereload}}}");
+            socket.onmessage = function (event) {
+                if (event.data === "reload") {
+                    socket.close();
+                    location.reload();
+                }
+            };
+            window.onbeforeunload = function() {
+                socket.close();
+            }
+        </script>
+        {{/if}}
+
+        {{#if google_analytics}}
+        <!-- Google Analytics Tag -->
+        <script type="text/javascript">
+            var localAddrs = ["localhost", "127.0.0.1", ""];
+            // make sure we don't activate google analytics if the developer is
+            // inspecting the book locally...
+            if (localAddrs.indexOf(document.location.hostname) === -1) {
+                (function(i,s,o,g,r,a,m){i['GoogleAnalyticsObject']=r;i[r]=i[r]||function(){
+                (i[r].q=i[r].q||[]).push(arguments)},i[r].l=1*new Date();a=s.createElement(o),
+                m=s.getElementsByTagName(o)[0];a.async=1;a.src=g;m.parentNode.insertBefore(a,m)
+                })(window,document,'script','https://www.google-analytics.com/analytics.js','ga');
+                ga('create', '{{google_analytics}}', 'auto');
+                ga('send', 'pageview');
+            }
+        </script>
+        {{/if}}
+
+        {{#if playground_line_numbers}}
+        <script type="text/javascript">
+            window.playground_line_numbers = true;
+        </script>
+        {{/if}}
+
+        {{#if playground_copyable}}
+        <script type="text/javascript">
+            window.playground_copyable = true;
+        </script>
+        {{/if}}
+
+        {{#if playground_js}}
+        <script src="{{ path_to_root }}ace.js" type="text/javascript" charset="utf-8"></script>
+        <script src="{{ path_to_root }}editor.js" type="text/javascript" charset="utf-8"></script>
+        <script src="{{ path_to_root }}mode-rust.js" type="text/javascript" charset="utf-8"></script>
+        <script src="{{ path_to_root }}theme-dawn.js" type="text/javascript" charset="utf-8"></script>
+        <script src="{{ path_to_root }}theme-tomorrow_night.js" type="text/javascript" charset="utf-8"></script>
+        {{/if}}
+
+        {{#if search_js}}
+        <script src="{{ path_to_root }}elasticlunr.min.js" type="text/javascript" charset="utf-8"></script>
+        <script src="{{ path_to_root }}mark.min.js" type="text/javascript" charset="utf-8"></script>
+        <script src="{{ path_to_root }}searcher.js" type="text/javascript" charset="utf-8"></script>
+        {{/if}}
+
+        <script src="{{ path_to_root }}clipboard.min.js" type="text/javascript" charset="utf-8"></script>
+        <script src="{{ path_to_root }}highlight.js" type="text/javascript" charset="utf-8"></script>
+        <script src="{{ path_to_root }}book.js" type="text/javascript" charset="utf-8"></script>
+
+        <!-- Custom JS scripts -->
+        {{#each additional_js}}
+        <script type="text/javascript" src="{{ ../path_to_root }}{{this}}"></script>
+        {{/each}}
+
+        {{#if is_print}}
+        {{#if mathjax_support}}
+        <script type="text/javascript">
+        window.addEventListener('load', function() {
+            MathJax.Hub.Register.StartupHook('End', function() {
+                window.setTimeout(window.print, 100);
+            });
+        });
+        </script>
+        {{else}}
+        <script type="text/javascript">
+        window.addEventListener('load', function() {
+            window.setTimeout(window.print, 100);
+        });
+        </script>
+        {{/if}}
+        {{/if}}
+
+    </body>
+</html>
\ No newline at end of file
diff --git a/docs/welcome_and_overview.md b/docs/welcome_and_overview.md
new file mode 100644
index 0000000000..30e75984d1
--- /dev/null
+++ b/docs/welcome_and_overview.md
@@ -0,0 +1,4 @@
+# Introduction
+
+Welcome to the documentation repository for Synapse, the reference
+[Matrix](https://matrix.org) homeserver implementation.
\ No newline at end of file