initiate fitting wrapper for generic fitting
add target function for test
add simple test
rewrite leastsq fit as a single function
add parameters class for fitting data
add args=() as input for fitting engine
test lmfit fitting class
add model folder with all functions for fitting
remove parameters, previously used for storing fitting inputs
update on background.py: license, docstring, input
add space to math equation, remove unused binning parameters
add more license
add __init__.py file
use proper index, use clip function to simplify the code
set bin value and window width as input
add more parameters in docstring
remove test function from background.py
use better index name instead of wo
add test folder for xrf_fit
remove space around = in inputs, change no_ as num_