[P] XetCache: Caching Jupyter Notebook Cells in GitHub for faster reruns

We created a plugin to easily cache the results of functions in jupyter notebook cells. The intermediate results are stored in a pickle file in the same folder.

This helps solve a few common pains we've experienced:

1. **accidentally overwriting variables**: You can re-run a given cell and re-populate any variable (e.g. if you reassigned \`df\` to some other value)\_
2. **sharing notebooks for others to rerun / reproduce**: Many collaborators don't have access to all the same clients / …

cache caching cells faster file functions github intermediate jupyter machinelearning notebook plugin solve variables