Move app menu in to app
https://developer.gnome.org/hig/stable/primary-menus.html
https://wiki.gnome.org/Design/Whiteboards/AppMenuMigration
Some apps already did this for 3.30.
https://developer.gnome.org/hig/stable/primary-menus.html
https://wiki.gnome.org/Design/Whiteboards/AppMenuMigration
Some apps already did this for 3.30.