gitlab: use CI for building website contents
gitlab: use CI for building website contents

Run the bare minimum build that is possible to create the docs, avoiding
compiling code which other jobs will deal with.

The generated website is published as an artifact and thus is browsable
by developers on build completion and can be downloaded as a zip file.

Reviewed-by: Andrea Bolognani <3ada0bee826c753786fdbba72243dfba997094cf@redhat.com>
Reviewed-by: Erik Skultety <2c14d38fa47c8799f1b9c16280abe27f8edfec6e@redhat.com>
Signed-off-by: Daniel P. Berrangé <bb938cf255e055ff3507f2627d214e8e62118fcf@redhat.com>

nertpinx/libvirt,jardasgit/libvirt,fabianfreyer/libvirt,libvirt/libvirt,libvirt/libvirt,nertpinx/libvirt,jfehlig/libvirt,crobinso/libvirt,zippy2/libvirt,fabianfreyer/libvirt,libvirt/libvirt,jardasgit/libvirt,olafhering/libvirt,zippy2/libvirt,fabianfreyer/libvirt,olafhering/libvirt,crobinso/libvirt,jfehlig/libvirt,nertpinx/libvirt,jardasgit/libvirt,olafhering/libvirt,fabianfreyer/libvirt,libvirt/libvirt,zippy2/libvirt,nertpinx/libvirt,olafhering/libvirt,crobinso/libvirt,crobinso/libvirt,jfehlig/libvirt,nertpinx/libvirt,zippy2/libvirt,jardasgit/libvirt,jfehlig/libvirt,jardasgit/libvirt,fabianfreyer/libvirt