Add npm publish

[jerger]

Sorry for not being careful for the 1.0.0 releasing process. But I think we should not go back in version no just to get a clean 1.0.0 ... :-(

What I've improved:

• Fixed the CI for PR-Requests
• enhanced release tags regex for being able to release also 0.0.0-dev-x tags
• added sha checksums (beeing uploaded in GH-releases section & packaged in npms tgz)
• added a first try for npm publish (dry-run at the moment)
• also fixed the dockerfile & README for using the new npm based installation.

The npm publish step requires a github-secret NPM_TOKEN.
You can create this on npm in the Auth-Token section & you can store this on Github in project-settings / secrets.

You can test the process if you push a tag like '1.0.1-dev-0'.
It should look somehow like https://github.com/DomainDrivenArchitecture/mastodon-bot/runs/819574051?check_suite_focus=true#step:11:1

If everything is fine, we can remove the dry-run, tag again and enjoy our first ci-driven version in GH releases and on npm.

[yogthos]

Ah no worries, we'll push out 1.0.1