Please document/describe how datacite-v*.json files are generated

## Is your feature request related to a problem? Please describe.

Thank you for taking care about maintaining jsonschema *serializations* of the datacite schema.

In light of the removal of `"identifiers"` from the jsonschema in 4.3 to 4.5 (just discovered #80), and

- https://github.com/datacite/schema/issues/149

we decided to look into how such files were generated. Unfortunately, we failed to find anything relevant in the 160250d6c7ebd39f24c93aa5dfdb4dea3169754b commit comment, or

- #94

## Describe the solution you'd like

A clear and concise description of how jsonschema json files are produced -- scripts which are run. And also when producing, which specifically datacite schema (4.5.1? 4.5.2? ... and ideally with the commit if not from versioned tag) was converted.

## Describe alternatives you've considered

one feasible and "complimentary alternative" could be to use [datalad run](https://handbook.datalad.org/en/latest/basics/basics-run.html) command to encode in the commit message what command produced the changes.