Sanitize 2 commits

[capital-G]

There are currently 2 commits on the main branch (1527729 and aafbaa3) which are not really tidied up for distribution and introduce ambiguous notebooks.
As those notebooks are quite big in filesize I think those should not be included in the history and should be reintroduced in a clean state.

This is a bit problematic as I want to add some stuff for tomorrow, maybe I will re-write the history and move the notebooks into a branch.

[capital-G]

Moved the 2 commits to branch https://github.com/capital-G/musikinformatik-sose2021/tree/sanitize-notebooks and did a reset --hard HEAD~2 and a push on the main branch so the 2 notebooks can be worked on separately for release.