ci: generate & publish docs

why not? also could help with newcomers
4 jobs for master in 5 minutes and 54 seconds (queued for 1 second)
Status Job ID Name Coverage
  Test
passed #932177
docs

00:02:41

passed #932175
flatpak
flatpak

00:04:48

passed #932176
lint

00:00:10

 
  Deploy
passed #932178
nightly

00:01:05