atlas-fit: Python tool to fit solar spectra to a known atlas

atlas-fit amends the results of spectroflat (ascl:2411.014) with calibration against a solar atlas. Data for wavelength calibration and continuum-correction is generated from flat field information and selected solar atlantes. The atlas-fit package provides two tools: one to generate a list of lines from the atlas and data to use for finding a wavelength solution (dispersion), and another to amend the calibration results from the spectroflat library.