Update to rwth.nb==0.1.7
For this, the feedback cells need to be desigend according to https://git.rwth-aachen.de/jupyter/rwth-nb/-/blob/development/docs/source/examples/RWTH%20Feedback.ipynb
For this, the feedback cells need to be desigend according to https://git.rwth-aachen.de/jupyter/rwth-nb/-/blob/development/docs/source/examples/RWTH%20Feedback.ipynb