DOC: fill in class names for rename methods (#21268)

(cherry picked from commit 7647969)

Author: gef756

pandas/core/frame.py

@@ -3721,7 +3721,7 @@ def rename(self, *args, **kwargs):
         copy : boolean, default True
             Also copy underlying data
         inplace : boolean, default False
-            Whether to return a new %(klass)s. If True then value of copy is
+            Whether to return a new DataFrame. If True then value of copy is
             ignored.
         level : int or level name, default None
             In case of a MultiIndex, only rename labels in the specified

pandas/core/series.py

@@ -3269,7 +3269,7 @@ def rename(self, index=None, **kwargs):
         copy : boolean, default True
             Also copy underlying data
         inplace : boolean, default False
-            Whether to return a new %(klass)s. If True then value of copy is
+            Whether to return a new Series. If True then value of copy is
             ignored.
         level : int or level name, default None
             In case of a MultiIndex, only rename labels in the specified