Adds Sphinx Documentation (#332)

* Add doxygen, breathe, sphinx documentation first steps

* Add draft readthedocs.yaml file

* Update to use exhale

* try forcing output

* Updated conf.py:

* Added conf.py new location

* Updated to fix typo

* Updated to re-add import

* update RTD.yaml

* Update to use correct doxygen command

* add docs env

* Test

* Remove exhale

* Remove not-working mod from all rst files

Co-authored-by: Kristin Berry <kberry@gyro.wr.usgs.gov>