Minor typo in "Bayesian Additive Regression Trees: Introduction" notebook

[mellorjc]

Bayesian Additive Regression Trees: Introduction:
https://github.com/pymc-devs/pymc-examples/blob/main/examples/case_studies/BART_introduction.myst.md:

Issue description

A minor typo error. The notebook contains the text "This plot helps us understand the season behind the bad performance" when it should say "This plot helps us understand the reason behind the bad performance"

Note that this issue tracker is about the contents in the notebooks, if
the notebook is instead triggering a bug or error in pymc, please
report to https://github.com/pymc-devs/pymc/issues instead

Expected output

The text should read "This plot helps us understand the reason behind the bad performance"

Proposed solution

The text should be changed to "This plot helps us understand the reason behind the bad performance"

[twiecki]

Want to do a PR that fixes it?