Move help from menubar to appmenu

as recommended by Gnome Human Interface Guidelines
3 jobs for help in 4 minutes and 40 seconds (queued for 7 seconds)
latest
Status Job ID Name Coverage
  Test
passed #2513
run-pylint

00:03:39

passed #2512
run-test

00:00:45

 
  Build
passed #2514
run-build

00:00:15