Doxygen improvements for sorc/grid_tools.fd/regional_esg_grid.fd/psym…

…2.f90 (#370)

* Part of Doxygen updates for sorc/grid_tools.fd #366
Doxygen update for regional_esg_grid.fd/psym2.f90

* Part of Doxygen updates for sorc/grid_tools.fd #366
modify grid_tools.fd/regional_esg_grid.fd/psym2.f90 with doxygen
improvement

* part of Doxygen updates for sorc/grid_tools.fd #366
sorc/grid_tools.fd/regional_esg_grid.fd/psym2.f90

* doxygen fixes

Co-authored-by: Edward Hartnett <Edward.Hartnett@noaa.gov>
Co-authored-by: Edward Hartnett <38856240+edwardhartnett@users.noreply.github.com>