Add release notes for Review Board 5.0.6.
Review Request #13267 — Created Sept. 11, 2023 and submitted — Latest diff uploaded
This contains fixes previously released in 6.0 beta 3, including upgrade
fixes, amysqlclientcap to fix major regressions in Linux distro
compatibility, and a number of other smaller bug fixes.
Built the docs. Checked for build errors, spelling errors, and bad links.