Statcast imputed-data derivation script

[bdilday]

I thought it might be useful to include the script I used to derive the statcast imputed values in the repo. This is good for reproducibility, but additionally this is coming up now because it looks like mlbam changed the data (seems they're no longer providing launch speed & angle on fouls and are rounding angles to integers?), meaning the imputation values probably need to be recomputed.