MNT: Use the correct letter casing for GridMET. [skip ci]

README.rst

@@ -56,7 +56,7 @@ PyNHD_           Navigate and subset NHDPlus (MR and HR) using web services
 Py3DEP_          Access topographic data through National Map's 3DEP web service      |py3dep|
 PyGeoHydro_      Access NWIS, NID, WQP, eHydro, NLCD, CAMELS, and SSEBop databases    |pygeohydro|
 PyDaymet_        Access daily, monthly, and annual climate data via Daymet            |pydaymet|
-PyGridMet_       Access daily climate data via GridMet                                |pygridmet|
+PyGridMET_       Access daily climate data via GridMET                                |pygridmet|
 PyNLDAS2_        Access hourly NLDAS-2 data via web services                          |pynldas2|
 HydroSignatures_ A collection of tools for computing hydrological signatures          |signatures|
 AsyncRetriever_  High-level API for asynchronous requests with persistent caching     |async|