[WIP] Add notebooks for machine learning in hydrology course

[Copilot]

Thanks for asking me to work on this. I will get started on it and keep this PR's description up to date as I form a plan and make progress.

Original prompt

Develop notebooks that pull in .py scripts to train students in my introduction to machine learning in hydrology course. I would like to have notebooks that cover random forest, xgboost, mlp, and lstm. The target feature of all datasets should be USGS NWIS streamflow (daily mean) and we can use input data from pydaymet.