Add whatsnew entry for nasa_power VARIABLE_MAP additions (PR pvlib#2762)

Author: karlhillx

docs/sphinx/source/whatsnew/v0.15.2.rst

@@ -28,6 +28,12 @@ Enhancements
 * Added mapping of the parameter ``"albedo"`` in
   :py:func:`~pvlib.iotools.get_nasa_power` when ``map_variables=True``
   (:pull:`2753`)
+* :py:func:`~pvlib.iotools.get_nasa_power` now maps additional NASA POWER
+  parameters to pvlib variable names when ``map_variables=True``:
+  ``temp_dew`` (T2MDEW), ``precipitable_water`` (TQV), and
+  ``relative_humidity`` (RH2M). Surface pressure (PS) is converted from
+  kPa to Pa, and precipitable water (TQV) from kg/m² to cm.
+  (:issue:`2731`, :pull:`2762`)
 
 
 Documentation