graphical-session.target is an existing target for the system. While I
don't use several X sessions, I prefer to have each service bound to
the right display and therefore, I create my own
graphical-session@.target for this purpose.
Also, I don't like having to use `systemctl --user enable`, so I
enable everything directly in graphical-session@.target. Other
dependencies are ordered from awesome@.service. This seems good
enough.
To me, I think it was cleaner to have a parameter with the current
display. This way, the session is specific to the current display. It
seems BindsTo doesn't think this way.
