feat(groups/{c,d,f,s}*): vim syntax support

Add vim modeline instructing the editor to use syntax plugin provided by apparmor.
Continuation of #392 to keep the diff list relatively short.

apparmor.d/groups/freedesktop/xwayland

@@ -38,3 +38,5 @@ profile xwayland @{exec_path} flags=(attach_disconnected) {
 
   include if exists <local/xwayland>
 }
+
+# vim:syntax=apparmor