Need better documentation for the meaning of some of the parameters

[emilydriano]

Per feedback from Aasli as an FPsim user, it's unclear what some of the model's scalar parameters are/how they should be parameterized. Example is the param 'high_parity_nonuse'; an explanation/comment next to the parameter in each location file (and possibly calibration file where it's used as a free param) would suffice.

[MObrien-IDM]

I'm starting to work on new documentation and will address this. Thank you!