Update docs/self-building.md

docs/self-building.md

@@ -25,8 +25,10 @@ List of roles where self-building the Docker image is currently possible:
 - `matrix-bridge-mautrix-facebook`
 - `matrix-bridge-mautrix-hangouts`
 - `matrix-bridge-mautrix-telegram`
+- `matrix-bridge-mautrix-signal`
 - `matrix-bridge-mx-puppet-skype`
 - `matrix-bot-mjolnir`
+- `matrix-bot-matrix-reminder-bot`
 
 Adding self-building support to other roles is welcome. Feel free to contribute!