update release notes, bump version

Update ReleaseNotes.md

add a forgotten library (rdkit#6326)

release prep (rdkit#6293)

* release prep

* typo

remove extra entry from release notes

update release notes

version bump

get ready for release

typo

Tag release and do final doc updates (rdkit#5669)

* tag release

* add registration hash to docs

* doc update for release

Updates for the beta release. (rdkit#5627)

* updates for the beta

* updates for the beta

* update

* add last PR