Add Mizoguci method into OptaDOS and info into Manual

[ajm143]

I have attached what I wrote for calculating the transition energy since that seemed to be the part of the manual that was missing for me, but the rest of it is there.

E_TE.pdf

[ajm143]

Mizoguchi is a written up python script that can be wrapped into optadpydos I think but It would also be nice to add into optados the ability to add a keyword mizoguchi : 1234 eV so that it just uses that to calculate.