Automate `README.md` updates

[jplewa]

Acceptance criteria

• Calling prepareReleaseAfterGeneratorUpdate or prepareReleaseOfUpdatedSchemas should create a commit which not only updates version-config.json, but also updates the version table in README.md
• Open question: there's also some versions in section 3. Add new or replace existing dependencies. I sometimes update them manually. Should they also get updated automatically>