REF: Fitter docstrings and code updated to conform to numpydoc standards
FIX: path to static and math rendering

mathjax replaced with pngmath
[skip ci]
REM: Remove extraneous :math: tags

[skip ci]
Unnecessary math tags removed from docstrings to be replaced with unicode values as appropriate
REF: Updated docstrings to contain methods sections

[skip ci]
REF: Updated docstrings to include attribute and methods
UPD: Docstring cleanup

docstrings cleaned up to remove unnecessary :math: tags
FIX: mode missing from __init__ and problem with build_Q

Build_Q combined with load_file had problem due to pre-existing Q