- Move some info to front-matter in the different security bulletins
such that it can be used when building the security bulleting index page.
- Update the security bulletin index page to show affected relesses and
impact score.
- Make it so table headers are vertically centered, which looks a lot nicer
when there are a combination of single-line and multi-line headers in the
same table.
- Add a few checks to correctly hide draft mode documents from sight
in more cases.
- Remove a stale document that's been in draft mode since first being
created in 2017.
- Clean up a bit of text in some release notes.