CI: build and deploy documentations
A first step towards better documentations of Mutter & it internal libraries
The current results can be viewed at:
- https://bilelmoussaoui.pages.gitlab.gnome.org/mutter/meta/
- https://bilelmoussaoui.pages.gitlab.gnome.org/mutter/cogl/
- https://bilelmoussaoui.pages.gitlab.gnome.org/mutter/clutter/
- https://bilelmoussaoui.pages.gitlab.gnome.org/mutter/cogl-pango
- https://bilelmoussaoui.pages.gitlab.gnome.org/mutter/cally/
I plan to submit other PRs in the future in order to port the documentations of all the items from gtk-doc to gi-docgen along with some g-i fixes and ideally have some landing page like https://docs.gtk.org/