add extras role

roles/extras/templates/config/mautrix-signal.yaml.j2

@@ -0,0 +1,17 @@
+{% extends 'mautrix-bridge.yaml.j2' %}
+
+{% block backfill %}
+{{ super() }}
+{% endblock %}
+
+{% block bridge %}
+    public_portals: true
+    relaybot: '@realaybot:{{ matrix_domain }}'
+{% endblock %}
+
+{% block additional %}
+signal:
+    avatar_dir: /var/lib/signald/data
+    data_dir: /var/lib/signald/data
+    delete_unknown_accounts_on_start: true
+{% endblock %}