need document all equation of state options

[danieljprice]

we need some documentation, ideally auto-generated from src/main/eos.F90, that documents what each equation of state option does (ieos=1,2,3,....)

The idea would be similar to the script docs/scripts/sink_particle_properties.pl which creates sinks.rst, or docs/scripts/print_setups.sh which creates setups.rst.

However implemented, auto-generation should be done as part of the docs/scripts/update_docs_from_code.sh script