Give instructions for feature extraction

[jccaicedo]

Two potential ways of obtaining features:

• using the notebook (https://github.com/broadinstitute/MorphEm/blob/nikita_nair/notebooks/Feature_Extraction.ipynb)
• downloading the features that we have (need to be posted in zenodo)

[jccaicedo]

Not a notebook anymore. It is a script with argparse parameters. Just add an example command to guide the user.

[jccaicedo]

Add the table with Expected Results to the README as a new section.

[jccaicedo]

Add a link to the PDF of the paper as follows: The paper is here (https://arxiv.org/pdf/2310.19224.pdf) and a short presentation here (https://neurips.cc/virtual/2023/poster/73620).