[Opm] Release 2021.10 timeline

[Atgeirr Rasmussen]

Dear all,

The next OPM release, 2021.10, is coming soon! Here is a preliminary timeline for the release process:

 - Feature freeze: Thursday October 14. Release branches will be created at this point.
 - First release candidate: Monday October 18.
 - Final release: Monday November 1.

Developers, please tag work that should be part of the release with the Release 2021.10 milestone tag. Such PRs will be prioritized for review and merging until the feature freeze.

Best,
Atgeirr

(Release manager for the 2021.10 release.)