[isabelle-dev] Towards the Isabelle2022 release

[Makarius]

Dear Isabelle contributors,

we are moving towards the Isabelle2022 release, which is planned for approx. 
20-Oct-2022.

See also 
https://isabelle-dev.sketis.net/phame/post/view/58/release_candidates_for_isabelle2022 
for ongoing activity (published release candidates etc.).

Now is the time to finish, wrap-up, update NEWS and CONTRIBUTORS. (I am myself 
still busy with updates on HTML presentation, and PDF document preparation).


	Makarius