Create a `RELEASE.md` that gives a checklist of actions needed for a public release

[davidhassell]

We need to make sure that items, such as updating pyfive.__init__.__version__, are done before a public release (it's current; still at 0.5.0.dev!). E.g. cfdm has https://github.com/NCAS-CMS/cfdm/blob/main/RELEASE.md. The checklist over at cdm has saved us all manner of pain.

If that's OK, I'll draft one in a PR ...

[kmuehlbauer]

Yes, I think __version__ in pyfive.__init__ should be removed. We should instead import from some version-file generated in the build process. All bits and peaces are in place in pyproject.toml (eg. usage of setuptools_scm). We would just need to add this version file to pyproject.toml. You can have a look at h5netcdf, how this is done there.

A document describing the release process will help indeed.

[valeriupredoi]

@kmuehlbauer done and merged in #152 😃

[bnlawrence]

Yes, dealing with my question on the pull request belongs here: exactly how does one change the version in the workflow of committing and releasing so that the version number is what we think it is? (Don't need to answer in a comment, it can be in the documentation itself.) Maybe that developer documentation we've been threatening.