Update docs for mautrix bridges: add instruction for sending "help" to the bot to the common guide

Signed-off-by: Suguru Hirahara <acioustick@noreply.codeberg.org>

docs/configuring-playbook-bridge-mautrix-bridges.md

@@ -159,6 +159,8 @@ To use the bridge, you need to start a chat with `@SERVICENAMEbot:example.com` (
 
 For details about the next steps, refer to each bridge's individual documentation page.
 
+Send `help` to the bot to see the available commands.
+
 If you run into trouble, check the [Troubleshooting](#troubleshooting) section below.
 
 ### Set up Double Puppeting (optional)

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

@@ -64,8 +64,6 @@ You can then follow instructions on the bridge's [official documentation on Auth
 
 After logging in, the bridge will create portal rooms for some recent direct messages.
 
-Send `help` to the bot to see the available commands.
-
 ### Bridge guilds
 
 If you'd like to bridge guilds, send `guilds status` to see the list of guilds, then send `guilds bridge GUILD_ID_HERE` for each guild that you'd like bridged. Make sure to replace `GUILD_ID_HERE` with the guild's ID.

docs/configuring-playbook-bridge-mautrix-slack.md

@@ -63,5 +63,3 @@ To use the bridge, you need to start a chat with `@slackbot:example.com` (where
 You can then follow instructions on the bridge's [official documentation on Authentication](https://docs.mau.fi/bridges/go/slack/authentication.html).
 
 If you authenticated using a token, the recent chats will be bridged automatically (depending on the `conversation_count` setting). Otherwise (i.e. logging with the Discord application), the chats the bot is in will be bridged automatically.
-
-Send `help` to the bot to see the available commands.