Publish to PyPi

[ColeDCrawford]

• [x] #12
• [x] determine group/maintainers for pypi and credentials
• [x] configure appropriate github secret for publishing on pypi
• [x] add pypi publish github action workflow
• [x] create a first release on github

[maltevogl]

We could also consider to setup an automated publishing to Zenodo on each release? https://zenodo.org/

[rlskoeser]

invited maintainers on DHTech slack; we have at least two now, will add others as they request; considering this task complete