feat(groups/g*): vim syntax support

Add vim modeline instructing the editor to use syntax plugin provided by apparmor.
Continuation of #393 to keep the diff list relatively short.

apparmor.d/groups/gnome/gnome-session-binary

@@ -162,3 +162,5 @@ profile gnome-session-binary @{exec_path} flags=(attach_disconnected) {
   include if exists <usr/gnome-session-binary.d>
   include if exists <local/gnome-session-binary>
 }
+
+# vim:syntax=apparmor