`qt_K` -> `qr` in Forward_modeling_for_Fe_I_lines_of_Kurucz.ipynb

[code29563]

I think something missing from this notebook is to divide qt_K determined in cell 5 by adbK.QTref_284[mask] before passing to SijT (or now line_strength) in the next cell, as the function requires qr: partition function ratio qr(T) = Q(T)/Q(Tref) for that argument. Could you confirm?