Mufasa

* Added new spectral model: N₂H⁺ (led by jcaza02)
* Patched likelihood calculation bugs for refits
* Made forward compatible with Python 3.12
* Added a new refitting method `'best_neighbour'`
* Added data visualization tools
* Added `refit_marginal` function to `master_fitter.py`

New Contributors
* taiwithers made their first contribution in https://github.com/mcyc/mufasa/pull/23
* jcaza02 made their first contribution in https://github.com/mcyc/mufasa/pull/36

This version (`v1.2.0`) revised how `MUFASA` calculates the AICc relative likelihood to that described by [Burnham & Anderson (2004)](https://doi.org/10.1177/0049124104268644) for least squares estimation with normally distributed errors.

`MUFASA`'s earlier implementation has been shown to be robust through rigorous tests against synthetic spectra (see [Chen, M. C-Y. et al. 2020](https://doi.org/10.3847/1538-4357/ab7378)). The improvements brought forward by this version tend to be found in marginal cases where two models provide comparable fits to the data.

The first Python 3 compatible version release

This version of `MUFASA` is the one used in Chen et al. "*Velocity-Coherent Filaments in NGC 1333: Evidence for Accretion Flow?*" ApJ (2020; submitted).