Update docs/sphinx/source/whatsnew/v0.16.0.rst

Co-authored-by: Cliff Hansen <cwhanse@sandia.gov>

Author: cbcrespo

docs/sphinx/source/whatsnew/v0.16.0.rst

@@ -6,7 +6,7 @@ v0.16.0
 
 Breaking Changes
 ~~~~~~~~~~~~~~~~
-* Remove empty ``poa_horizon`` component from the output of
+* Remove empty ``poa_horizon`` key from the ``diffuse_components`` output of
   :py:func:`pvlib.irradiance.haydavies` when ``return_components=True``.
   (:pull:`2788`)