Clarified 'Whats New' Language

Author: drewmassey

doc/source/whatsnew/v0.23.1.txt

@@ -119,4 +119,4 @@ Other
 
 - Tab completion on :class:`Index` in IPython no longer outputs deprecation warnings (:issue:`21125`)
 - Bug preventing pandas from being importable with -OO optimization (:issue:`21071`)
-- Timestamp resolution returns a :class:`Timedelta` rather than a normal `timedelta` object (:issue:`21336`)
+- Timestamp resolution returns a :class:`Timedelta` (in nanoseconds) rather than a normal `timedelta` object (in microseconds) (:issue:`21336`)