Update v0.13.1.rst

Author: RDaxini

docs/sphinx/source/whatsnew/v0.13.1.rst

@@ -23,6 +23,8 @@ Enhancements
 
 Documentation
 ~~~~~~~~~~~~~
+* Substantiate definitions of solar/surface azimuth/zenith and aoi on the
+  :ref:`nomenclature` page. (:issue:`2448`, :pull:`2503`)
 
 
 Testing
@@ -45,3 +47,5 @@ Maintenance
 Contributors
 ~~~~~~~~~~~~
 * Elijah Passmore (:ghuser:`eljpsm`)
+* Rajiv Daxini (:ghuser:`RDaxini`)
+* Omar Bahamida (:ghuser:`OmarBahamida`)