Add a Sphinx project

This introduces a Sphinx documentation project and associated CI job. It includes a minimal index page which will be expanded as individual pages are added to the project.

The plan is to use the current wiki as a source for this new documentation project and convert or rewrite things page-by-page. At some point in the future we can set up redirects or otherwise point folks who arrive at the old wiki pages to equivalent pages (or the home page if no equivalent exists in the new documentation) and switch over.

These files, except for the index page, were auto-generated with sphinx-quickstart.

Signed-off-by: Jeremy Cline jcline@redhat.com