Release needed to support an IceCube code review.
Multiple quality of life improvements.
* Improved documentation, including an action to show docs on github-pages.
* Firesong can now be imported to produce a dictionary of neutrino
sources
* Speed improvements. Good for high density settings
* Updated default values for diffuse muon neutrino flux, Planck 2018
cosmological parameters, Madau and Dickinson 2016 is the default
evolution.
* Expanded unit testing
* Removed NeutrinoAlert.py
* Removed non-FIRESONG code related to CTA