Create github workflow for automatic packaging and API-documentation upload

[dkrako]

Description of the problem

Currently when creating new package versions, all packaging/building/uploading steps have to be done manually. This can be integrated into github workflows via twine: https://pypi.org/project/twine/

Description of a solution

Setup github workflow and secrets to automatically upload package to pypi and update documentation on readthedocs.

Minimum acceptance criteria

• [ ] automatic pypi upload
• [x] automatic readthedocs upload

[dkrako]

readthedocs are now autouploaded when adding a tag to commit. autopacking is left to do.