Start migrating config to Ansible

The real file still lives in /opt/mailman on the host for now, need to migrate whole config into Ansible.

resources/chaosknoten/lists/docker_compose/compose.yaml.j2

@@ -37,7 +37,6 @@ services:
       - database:database
     volumes:
       - /opt/mailman/web:/opt/mailman-web-data
-      - ./configs/mailman-extra.cfg:/opt/mailman/core/mailman-extra.cfg
       - ./configs/settings_local.py:/opt/mailman-web/settings_local.py
       - ./files/templates:/opt/mailman-web/templates
     environment:

resources/chaosknoten/lists/docker_compose/mailman-extra.cfg

@@ -4,3 +4,16 @@
 
 [mailman]
 pending_request_life: 7d
+
+# This address is the "site owner" address.  Certain messages which must be
+# delivered to a human, but which can't be delivered to a list owner (e.g. a
+# bounce from a list owner), will be sent to this address.  It should point to
+# a human.
+site_owner: listops@hamburg.ccc.de
+
+[mta]
+# remove any pre-existing DKIM headers from mails being forwarded through a
+# list
+remove_dkim_headers: yes
+
+# eof