Merge branch 'fix-biomin-someobviousindescription' into 'master'

This concerns only wording and spelling. At some places I found the explanations could be a bit more clear or precise. That's it already for the moment.

added Cleanup label

requested review from @hommel

assigned to @hommel

approved this merge request

The pipeline failed. I'm not sure about the whether it should be still merged as I am not sure whether the pipeline-system works for the dumux-course. Also, Holger's changes should not actually do anything to the code, as they are only modifications of the comments.

approved this merge request

enabled an automatic merge when the pipeline for 7a23b046 succeeds

mentioned in commit 36776883

merged