Clean Up Repo and make it public

Before we add the link to this repo to pypi, we should clean up the repo. that includes:

• remove unused branches
• check visibility settings for all project features #84
• check for secret and data leaks #85

Note: sqa (see pipeline) already runs gitleaks, but we could adjust rules etc. because historically we had data in this repo, it might be wise to purge the commits from the repo

• add logo to the project #86
• turn visibility to public #87