add note to explain columns parameter inside rename_axis() (pandas-dev#34194)

Author: gabsmoreira

pandas/core/generic.py

@@ -1012,6 +1012,9 @@ def rename_axis(self, mapper=lib.no_default, **kwargs):
         index, columns : scalar, list-like, dict-like or function, optional
             A scalar, list-like, dict-like or functions transformations to
             apply to that axis' values.
+            Note that the ``columns`` parameter is not allowed if the
+            object is a Series. This parameter only apply for DataFrame
+            type objects.
 
             Use either ``mapper`` and ``axis`` to
             specify the axis to target with ``mapper``, or ``index``