Improve the rmtree doc for dir_fd param addition in 3.11 (python#118964)

Author: sobolevn

Doc/library/shutil.rst

@@ -338,7 +338,7 @@ Directory and files operations
       before removing the junction.
 
    .. versionchanged:: 3.11
-      The *dir_fd* parameter.
+      Added the *dir_fd* parameter.
 
    .. versionchanged:: 3.12
       Added the *onexc* parameter, deprecated *onerror*.