add a release helper tool

[pamapa]

• something with an interactive mode, where you are guided and you can choose version (then adds version into package.json, commit, tag, push, No publish to npm, as we use our CI for that. No github release, shall be done manually to trigger a npm release)
• such that other maintainers than me can publish in a same defined way

Candidates:

• https://github.com/release-it/release-it#readme
• https://github.com/conventional-changelog/standard-version (no interactive mode)

[pamapa]

I am not so sure if its worth all the additional dev dependencies, e.g. release-it can do much more, which we do not need...