meson: Implement developer documentation build

Signed-off-by: Povilas Kanapickas <povilas@radix.lt>
5 jobs for meson-docs in 7 minutes and 15 seconds (queued for 3 seconds)
Status Name Job ID Coverage
  Docker Image
passed debian-buster #12968887

00:00:24

 
  Build And Test
passed autotools #12968888

00:06:50

passed meson #12968889

00:01:46

passed meson-noglamor #12968890

00:01:26

passed mingw-cross-build #12968891

00:01:10