Adding user option to template

Some containers do not support PUID and GUID, in that case it is handy to have an option to pass the user to the container from the compose file

templates/docker-compose.yml.j2

@@ -154,6 +154,9 @@ services:
       - {{ envfile }}
 {% endfor %}
 {% endif %}
+{% if container.user is defined %}
+    user: {{ container.user }}
+{% endif %}
 {% if container.restart is defined %}
     restart: {{ container.restart }}
 {% endif %}