[ ] Custom markdown checks for bssw.io/redcarpet quirks
[ ] Title uniqueness (this is causes problems in the bssw.io front-end) -- front-end now handles collisions better, though they're still not desirable. This could probably be de-prioritized or removed.
This issue is to start collecting in one place a list of tests that might be useful to apply via GH actions as part of a PR testing workflow.