Fixes #5174. The F1 key will now open Geary help.
Fixes #5174. The F1 key will now open Geary help.

glebihan/geary,mjog/geary,orlandosanchez/geary,didrocks/geary,githubnemo/geary,aatishnn/geary,emersion/geary,kyoushuu/geary,emersion/geary,robol/geary,kpiwko/geary,geekvigilante/geary,mjog/geary,martinra/geary,jimbonator/geary,martinra/geary,mpdeimos/geary,tshikaboom/geary,rschroll/geary,jimbonator/geary,aatishnn/geary,rschroll/geary,AtticHacker/geary,martinra/geary,emersion/geary,AtticHacker/geary,dominickm/Geary,abn/geary,tshikaboom/geary,aatishnn/geary,orlandosanchez/geary,MohamedIM/geary-unofficial,githubnemo/geary,githubnemo/geary,robol/geary,mjog/geary,tshikaboom/geary,glebihan/geary,jimbonator/geary,orlandosanchez/geary,dominickm/Geary,glebihan/geary,robol/geary,AtticHacker/geary,kyoushuu/geary