4.0 Beta 3 launch

- add some more docs as well as version bump
- changelog(!)
3 jobs for 4.0-beta3 in 2 minutes and 8 seconds
latest
Status Job ID Name Coverage
  Build
passed #4098
build

00:01:22

 
  Deploy
passed #4099
pages

00:00:45

passed pages:deploy

00:00:00