Update Doc/whatsnew/3.15.rst

Co-authored-by: Victor Stinner <vstinner@python.org>

Author: jsbueno

Doc/whatsnew/3.15.rst

@@ -806,7 +806,7 @@ json
 
 * Add the *array_hook* parameter to  :func:`~json.load` and
   :func:`~json.loads` functions:
-  Allow a callback for JSON literal array types to customize Python lists in
+  allow a callback for JSON literal array types to customize Python lists in
   the resulting decoded object. Passing combined :class:`frozendict` to
   *object_pairs_hook* param and :class:`tuple` to ``array_hook`` will yield a
   deeply nested immutable Python structure representing the JSON data.