GitLab

Change the version from which the release script is used.
Also explain the prefixes used in the commits.

Closes #29294

and move contributing from the root directory to the docs/ one,
since it links to testing but testing is not in the root directory.
This way when a user only reads the readme locally, does not try
to find testing in the root directory and instead will search for
more documentation in docs/.

So that when running linkcheck does not obtain forbidden.

Instead create a changelog before new releases.

Closes ticket #28572.

the reference to how to write commit messages should be enough.

since it is not anymore used

- Also do some switching away from time_now() back to time.time()
GH: ref #67

- Add note in CONTRIBUTING to prefer UTC and timestamps

- Fix things that broke when switching from date to datetime.

GH: closes #113