Pathfinder notebook update

[fonnesbeck]

This replaces the troublesome 8-schools example(!) with a simple logistic regression for classification.

• Notebook follows style guide https://docs.pymc.io/en/latest/contributing/jupyter_style.html
• PR description contains a link to the relevant issue:
  • a tracker one for existing notebooks (tracker issues have the "tracker id" label)
  • or a proposal one for new notebooks
• Check the notebook is not excluded from any pre-commit check: https://github.com/pymc-devs/pymc-examples/blob/main/.pre-commit-config.yaml

---

📚 Documentation preview 📚: https://pymc-examples--702.org.readthedocs.build/en/702/

[review-notebook-app]

Check out this pull request on 

See visual diffs & provide feedback on Jupyter Notebooks.

---

Powered by ReviewNB

[fonnesbeck]

Sorry for the messy merge messages -- not sure why they are there, but squash-merge should deal with them.

[twiecki]

Can we make it somewhat more interesting, something that maybe shows the scaling properties, like a very dimensional logistic regression?

[fonnesbeck]

Decided to remove this notebook and replace it when the Pathfinder implementation is updated.