Add Jupyter or Colab notebooks

[daemon]

Title says it all.

[mrkarezina]

Hi Ralph, have you already started working on a Colab notebook? I was trying to get more familiar with the project so I might end up making a notebook in the process.

What would be helpful to include or test in the notebook?

[daemon]

Hey, sounds good. No, I haven't started -- a getting started guide for BM25 would probably be the best, since everyone can run BM25 with or without a GPU. Beyond that, T5 is probably the next most important due to its high quality.

[mrkarezina]

Sounds good, i'll get started on that.

[ronakice]

Resolved in #18