Update docs/configuring-playbook-bridge-mautrix-whatsapp.md: remove description for relay-bot

For WhatsApp the default relay mode is used and the description for it is available on the common guide for configuring mautrix bridges.

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

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

@@ -22,20 +22,6 @@ matrix_mautrix_whatsapp_enabled: true
 
 Whatsapp multidevice beta is required, now it is enough if Whatsapp is connected to the Internet every 2 weeks.
 
-The relay bot functionality is off by default. If you would like to enable the relay bot, add the following to your `vars.yml` file:
-
-```yaml
-matrix_mautrix_whatsapp_bridge_relay_enabled: true
-```
-
-By default, only admins are allowed to set themselves as relay users. To allow anyone on your homeserver to set themselves as relay users add this to your `vars.yml` file:
-
-```yaml
-matrix_mautrix_whatsapp_bridge_relay_admin_only: false
-```
-
-If you want to activate the relay bot in a room, send `!wa set-relay`. To deactivate, send `!wa unset-relay`.
-
 ### Extending the configuration
 
 There are some additional things you may wish to configure about the bridge.