[INFRA] Automate tag and files update

[tbouffard]

Currently (in v0.2.1), the version must be updated prior and after releasing (by creating a PR). This is painful and error prone
The git tag is created only when the GitHub release is published.

I suggest we do something like for the bpmn-visualization TypeScript library.
We provide a GitHub workflow that will do everything for us:

• It takes as an input the version to release.
• it updates the files with the new version and commit
• then it creates the related tag
• then it updates the files with the development version and commit
• finally, it push the changes and the tag

If possible, the development version should be automatically computed by the workflow to avoid human error

Tasks to do

Add a Github workflow triggered by workflow_dispatch (manual run)

• pass the new version
• update the files containing the version accordingly (see MAINTAINERS.md)
• create the git tag
• set the development version accordingly (see MAINTAINERS.md)
• push all commits and the tag

Documentation

• update MAINTAINERS.md to explain the new release process

Notes

• remember that the GH_TOKEN has readonly permissions by default
• check how we proceed in the bpmn-visualization-js repo
• don't forget to use the playground repository for testing