Community Outreach Revamp Knowledge Base: Add redirects
This commit sets up page aliases, or redirects, from the CommOps docs
pages that would exist for the Join SIG.
I also made some minor changes:
* Fix headings to match H1, H2, instead of starting H2, H3
* Update partial syntax to the new syntax for Antora
Signed-off-by: Justin W. Flory (he/him) [Fedora Project] <jwf@fedoraproject.org>