Add release notes for Review Board 3.0.24.
Review Request #11659 — Created June 15, 2021 and submitted — Latest diff uploaded
This is a small release fixing a few bugs with Markdown, Subversion, and
cookies. It also improves performance with some common queries and
introduces a feature for adding known safe URL protocols for Markdown
Built the docs. Checked for build errors, spelling errors, and bad links.