Release procedures, take 2

[lars-t-hansen]

We will need to have slightly more rigorous release procedures if we are going to pull from the repo automatically to update sonar on the clusters (as per request). I'm not sure what best practice is as this is not quite my field. My gut feeling, given how few people we are and how few fixes we land, is to branch from main every time we update the minor release number - this is a release - and then increment the bugfix version on that branch as bugfixes land, and uplift bugfixes to main as necessary; maybe a tag on the tip of the latest release branch will allow others to pull latest stable easily. Discuss.

[lars-t-hansen]

To that end, I will:

• create a release branch in this repo for 0.12 based on today's code
• update the version number to 0.12.1 since there have been various fixes since the version number was bumped to 0.12
• document release procedures in the README

The procedures will be detailed in the bug but will pertain to branching, uplifting fixes from release branches to main, and backporting fixes from main to release branches.

The new branch will itself serve as an example of these rules since the changes to the README will need to be uplifted to main and main itself will need to be bumped to v0.13.0.

[lars-t-hansen]

Fixed in repo.