fix grappa install in the colab notebook "Grappa-dataset.ipynb" linked in the README.txt

[emerbitz]

Currently, the colab notebook "Grappa-dataset.ipynb" installes grappa from source and crashs.

Reason: Colab uses python v3.12.12. The cpu_requirements.txt from Grappa need torch==2.0.0, which is not compatible with python v3.12.12.

Possible solutions:
a) Change python version in colab
b) Install grappa via pypi (no gpu support)

[emerbitz]

Moreover, in the install section:

!cd grappa_repo && git checkout origin/tutorials

has not effect, as the branch does no longer exist.

[emerbitz]

In the colab notebook, Grappa install via pypi with

!pip install grappa-ff

also crashes due the python version used by colab. Therefore, the other colab tutorial notebooks are likely also effected.

[emerbitz]

We could switch from colab to deepnote. In deepnote, one can select different python versions.