added new options to mautrix-signal config template

roles/custom/matrix-bridge-mautrix-signal/templates/config.yaml.j2

@@ -87,15 +87,15 @@ metrics:
 # Bridge config
 bridge:
     # Localpart template of MXIDs for Signal users.
-    # {{.}} is replaced with the internal ID of the Signal user.
-    username_template: signal_{{.}}
+    # {{ '{{.}}' }} is replaced with the internal ID of the Signal user.
+    username_template: "{{ 'signal_{{.}}' }}"
     # Displayname template for Signal users. This is also used as the room name in DMs if private_chat_portal_meta is enabled.
     # {{.ProfileName}} - The Signal profile name set by the user.
     # {{.ContactName}} - The name for the user from your phone's contact list. This is not safe on multi-user instances.
     # {{.PhoneNumber}} - The phone number of the user.
     # {{.UUID}} - The UUID of the Signal user.
     # {{.AboutEmoji}} - The emoji set by the user in their profile.
-    displayname_template: '{{or .ProfileName .PhoneNumber "Unknown user"}}'
+    displayname_template: "{{ '{{.ProfileName}} (Signal)' }}"
     # Whether to explicitly set the avatar and room name for private chat portal rooms.
     # If set to `default`, this will be enabled in encrypted rooms and disabled in unencrypted rooms.
     # If set to `always`, all DM rooms will have explicit names and avatars set.