Add/review crs for Red River data

Add (or review for accuracy if it already exists) crs information to Red River datasets, which likely have the same crs (but please check this):

• s3://mdmf/gdp/Red_River_future.zarr
• s3://mdmf/gdp/Red_River_historical.zarr
• s3://mdmf/gdp/Red_River_MPI-ESM-LR_future.zarr
• s3://mdmf/gdp/Red_River_MPI-ESM-LR_historical.zarr

UPDATE (Red River obs):

• s3://mdmf/gdp/red_river_obs_livneh.zarr

They have the following THREDDS catalog entries, if that is helpful to have:

• https://cida.usgs.gov/thredds/catalog.html?dataset=cida.usgs.gov/RedRiver_future
• https://cida.usgs.gov/thredds/catalog.html?dataset=cida.usgs.gov/RedRiver_historical

Note: There are only 2 THREDDS catalog entries for this dataset - each was broken into two zarrs because they have different time steps or calendars (or something to that effect), I believe.