Improve release docs

[znicholls]

Pull request

Please confirm that this pull request has done the following:

• Hotfix pip install test #93
• Tests added (N/A)
• Documentation added (where applicable)
• Example added (either to an existing notebook or as a new notebook, where applicable)
• Description in CHANGELOG.rst added

Adding to CHANGELOG.rst

Please add a single line in the changelog notes similar to one of the following:

- (`#XX <https://github.com/znicholls/silicone/pull/XX>`_) Added feature which does something
- (`#XX <https://github.com/znicholls/silicone/pull/XX>`_) Fixed bug identified in (`#YY <https://github.com/znicholls/silicone/issues/YY>`_)

[znicholls]

Questions for @Rlamboll and @jkikstra on top of general review:

• would a link to an explanation of how semantic versioning works be useful?
• would a link to an explanation of how versioneer works be useful (e.g. 0.2.0 isn't a valid tag I don't think @Rlamboll)?
• do you want a stronger protocol for deciding when we make new versions (my opinion has always been that releases are basically free so it's not worth stressing about but others are much stricter e.g. pyam)?

You can see the CI-CD pipeline doing it's thing in the pipelines for the v0.1.0rc tag and the 0.2.0 tag.

[Rlamboll]

That is a lot simpler than before!

[Rlamboll]

Questions for @Rlamboll and @jkikstra on top of general review:

• would a link to an explanation of how semantic versioning works be useful?
  Not really, we can google it
• would a link to an explanation of how versioneer works be useful (e.g. 0.2.0 isn't a valid tag I don't think @Rlamboll)?
  Yes, I'm surprised that finding the documentation for how to use it (rather than what the codebase is) is so difficult.
• do you want a stronger protocol for deciding when we make new versions (my opinion has always been that releases are basically free so it's not worth stressing about but others are much stricter e.g. pyam)?
  No, large version numbers are fine

You can see the CI-CD pipeline doing it's thing in the pipelines for the v0.1.0rc tag and the 0.2.0 tag.
Indeed, I apparently pip-installed it correctly (it ignores the 0.2.0 version).

[Rlamboll]

It doesn't actually pass the tests however, I get
from openscm_units.unit_registry import ScmUnitRegistry
E ModuleNotFoundError: No module named 'openscm_units'

(I have openscm-units installed in this env and this persists even if I revert to openscm-units 0.1.1, which is what I was previously using.) Will have another look in the morning.

[znicholls]

It doesn't actually pass the tests

As in make test-pypi-install doesn't work? Everything works on the CI servers from what I can tell.

[Rlamboll]

I wasn't running make because windows. I've tried it again and it works now, so I'm not sure what the problem was (I cleared the cache). Anyway, it seems to work for Joeri when installed everything from scratch, so presumably a problem connected to conda recovering old versions of files somehow?

[znicholls]

Ye weird, sometimes things don’t reinstall properly unless you start fresh..

[znicholls]

After #93 I think this is good to go too @Rlamboll

[Rlamboll]

OK @znicholls, I don't think Jarmo is going to review this so merge them at will