Greetings Testers!
Release notes are available here:
As usual the release notes are provided as both delta/differential and in full, and links to the issue tracker are provided where available. Also note that we have skimmed more known issues in the interest of transparency. This does not mean that there are more known issues in this release; rather, that we have taken greater care to compile the list.
Docs are available online at Unity - Manual: Unity Manual
(though note that they are updated at a different rate from the release)
Please remember to back up your projects before opening them in the beta build.