[isabelle-dev] Isabelle2021 release process

[Makarius]

We are in an early stage of the official Isabelle2021 release process.

The blog https://isabelle-dev.sketis.net/phame/blog/view/2 and the workboard
https://isabelle-dev.sketis.net/project/board/4 provide a clue where we are.

Presently, the repository is still open for commits for that branch, at least
until the end of the Christmas season (10-Jan-2021).


	Makarius