Add a notebook to look at the prod data

[simlmx]

In particular, compare the forecasts with the ground truth generation values, for different horizons.

[codecov[bot]]

Codecov Report

Merging #55 (e033ec0) into main (bb0bc55) will decrease coverage by 2.66%. The diff coverage is n/a.

@@            Coverage Diff             @@
##             main      #55      +/-   ##
==========================================
- Coverage   94.32%   91.66%   -2.66%     
==========================================
  Files           9        1       -8     
  Lines         317       60     -257     
==========================================
- Hits          299       55     -244     
+ Misses         18        5      -13     

see 8 files with indirect coverage changes

:mega: We’re building smart automated test selection to slash your CI/CD build times. Learn more