docs(python): Add a Plotnine example to the visualization docs

[jrycw]

This PR adds Plotnine to the visualization docs.

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 79.75%. Comparing base (241d34b) to head (8bafe2f).
Report is 2 commits behind head on main.

Additional details and impacted files

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  Coverage   79.75%   79.75%           
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  Files        1604     1604           
  Lines      231519   231519           
  Branches     2639     2639           
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+ Hits       184640   184649    +9     
+ Misses      46270    46261    -9     
  Partials      609      609           

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[MarcoGorelli]

thanks @jrycw - I presume you build this locally and verified that it renders fine?

It supports Polars DataFrame by internally converting it to a pandas DataFrame.

it does for now 😉 but I've heard that this might be changing at some point

[jrycw]

@MarcoGorelli, I ran this locally and here's the final figure (hope I got it right—still a newbie to Plotnine).

[MarcoGorelli]

thanks!