Update migration guide
authorMatthias Clasen <mclasen@redhat.com>
Mon, 6 Apr 2020 17:48:57 +0000 (13:48 -0400)
committerMatthias Clasen <mclasen@redhat.com>
Mon, 6 Apr 2020 20:32:03 +0000 (16:32 -0400)
commite7a8a4eb0605d0c0e0849501b6cad1da82d590ed
tree91c73bd3837ea5308319d5c832295eaa9859e172
parent70fbf8dbb6038989488c94d8670668c65068173e
Update migration guide

Rewrite the sections about keymaps and menus, and add
hints about modifiers.
docs/reference/gtk/migrating-3to4.xml