docs(appservice-discord): improve and expand bridging method docs

docs/configuring-playbook-bridge-appservice-discord.md

@@ -23,18 +23,51 @@ matrix_appservice_discord_bot_token: "YOUR DISCORD APP BOT TOKEN"
 ```
 
 5. If you've already installed Matrix services using the playbook before, you'll need to re-run it (`--tags=setup-all,start`). If not, proceed with [configuring other playbook services](configuring-playbook.md) and then with [Installing](installing.md). Get back to this guide once ready.
-6. Retrieve Discord invite link from the `{{ matrix_appservice_discord_config_path }}/invite_link` file on the server (this defaults to `/matrix/appservice-discord/config/invite_link`). You need to peek at the file on the server via SSH, etc., because it's not available via HTTP(S).
-7. Invite the Bot to Discord servers you wish to bridge. Administrator permission is recommended.
-8. Room addresses follow this syntax: `#_discord_guildid_channelid`. You can easily find the guild and channel ids by logging into Discord in a browser and opening the desired channel. The URL will have this format: `discordapp.com/channels/guild_id/channel_id`. Once you have figured out the appropriate room addrss, you can join by doing `/join #_discord_guildid_channelid` in your Matrix client.
 
 Other configuration options are available via the `matrix_appservice_discord_configuration_extension_yaml` variable.
 
+## Self-Service Bridging (Manual)
 
-## Getting Administrator access in a room
+Self-service bridging allows you to bridge specific and existing Matrix rooms to specific Discord rooms. This is disabled by default, so it must be enabled by adding this to your `vars.yml`:
+
+```yaml
+matrix_appservice_discord_bridge_enableSelfServiceBridging: true
+```
+
+_Note: If self-service bridging is not enabled, `!discord help` commands will return no results._
+
+Once self-service is enabled:
+
+1. Start a chat with `@_discord_bot:<YOUR_DOMAIN>` and say `!discord help bridge`.
+2. Follow the instructions in the help output message. If the bot is not already in the Discord server, follow the provided invite link. This may require you to be a administrator of the Discord server.
+
+_Note: Encrypted Matrix rooms are not supported as of writing._
+
+On the Discord side, you can say `!matrix help` to get a list of available commands to manage the bridge and Matrix users.
+
+## Portal Bridging (Automatic)
+
+Through portal bridging, Matrix rooms will automatically be created by the bot and bridged to the relevant Discord room. This is done by simply joining a room with a specific name pattern (`#_discord_<guildID>_<channlID>`).
+
+All Matrix rooms created this way are **listed publicly** by default, and you will not have admin permissions to change this. To get more control, [make yourself a room Administrator](#getting-administrator-access-in-a-portal-bridged-room). You can then unlist the room from the directory and change the join rules.
+
+If you want to disable portal bridging, set the following in `vars.yml`:
+
+```yaml
+matrix_appservice_discord_bridge_disablePortalBridging: true
+```
+
+To get started with Portal Bridging:
+
+1. To invite the bot to Discord, retrieve the invite link from the `{{ matrix_appservice_discord_config_path }}/invite_link` file on the server (this defaults to `/matrix/appservice-discord/config/invite_link`). You need to peek at the file on the server via SSH, etc., because it's not available via HTTP(S).
+2. Room addresses follow this syntax: `#_discord_<guildID>_<channelID>`. You can easily find the guild and channel IDs by logging into Discord in a browser and opening the desired channel. The URL will have this format: `discord.com/channels/<guildID>/<channelID>`.
+3. Once you have figured out the appropriate room address, you can join by doing `/join #_discord_<guildID>_<channelID>` in your Matrix client. 
+
+## Getting Administrator access in a portal bridged room
 
 By default, you won't have Administrator access in rooms created by the bridge.
 
-To [adjust room access privileges](#adjusting-room-access-privileges) or do various other things (change the room name subsequently, etc.), you'd wish to become an Administrator.
+To adjust room access privileges or do various other things (change the room name subsequently, etc.), you'd wish to become an Administrator.
 
 There's the Discord bridge's guide for [setting privileges on bridge managed rooms](https://github.com/Half-Shot/matrix-appservice-discord/blob/master/docs/howto.md#set-privileges-on-bridge-managed-rooms). To do the same with our container setup, run the following command on the server:
 
@@ -42,12 +75,3 @@ There's the Discord bridge's guide for [setting privileges on bridge managed roo
 docker exec -it matrix-appservice-discord \
 /bin/sh -c 'cp /cfg/registration.yaml /tmp/discord-registration.yaml && cd /tmp && node /build/tools/adminme.js -c /cfg/config.yaml -m "!ROOM_ID:SERVER" -u "@USER:SERVER" -p 100'
 ```
-
-
-## Adjusting room access privileges
-
-All rooms created by the bridge are **listed publicly** in your server's directory and **joinable by everyone** by default.
-
-To get more control of them, [make yourself a room Administrator](#getting-administrator-access-in-a-room) first.
-
-You can then unlist the room from the directory and change the join rules.