Greg Myers authored 5 years ago and Achilleas Pipinellis committed 5 years ago

Updates doc/policy/maintenance.md, adds upgrade path from 11 -> 12

Marcel Amirault authored 5 years ago and Evan Read committed 5 years ago

Updating redirected links in the development, install, policy
raketasks and university dirs. Should now link to final
URL to avoid redirect hops

- Also makes other minor Markdown fixes that were near the main fixes.

Due to a missing `s`, a link to the blog archive
for releases was broken.

Make clear that we may backport bug fixes to the previous stable
release.

Signed-off-by: Rémy Coutable <remy@rymai.me>