[ci skip] Update README with SBX

Update changelog and cleanup (DLR-RM#1434)

Release v1.7.0 (DLR-RM#1268)

Update license file parameter

Release v1.6.1 (DLR-RM#1080)

Release v1.6.0 (DLR-RM#958)

* Release v1.6.0 + update doc + add copy button

* Update read the doc conda env

* Update year

* Fix bug in kl divergence check

* Rephrase requirement for envpool and isaac gym

Release v1.5.0 (DLR-RM#835)

* Release v1.5.0

* Fix link

Release 1.4.0 (DLR-RM#729)

* Release 1.4.0

* Add integration section in the readme

Release 1.3.0 (DLR-RM#625)

Hotfix for Vecnormalize (DLR-RM#558)

* Hotfix for Vecnormalize

* Rename `ret` to `returns`