ci: generate & publish docs

why not? also could help with newcomers
3 jobs for bilelmoussaoui/docs in 5 minutes and 16 seconds (queued for 1 second)
Status Job ID Name Coverage
  Test
passed #926856
docs

00:05:16

passed #926854
flatpak
flatpak

00:04:43

passed #926855
lint

00:00:10