Review documentation for release infrastructure

This PR should add documentation for the new CI release infrastructure including:

- graphs and descriptions of the various jobs involved in the release workflow
- address of the CI release servers used for the integration testing
- switch to https for the CI servers


NB: this PR is not expected to cover the new C++ release jobs. A separate PR will be opened for these once this is merged.

--no-rebase
There's something funny going on with the formatting here because this line appears in bold on https://www.openmicroscopy.org/site/support/contributing-staging/release-process.html#id1 but I have no idea why! You also don't need the BF job on a separate line.