bpo-29481: add versionadded 3.6.1 to typing.Deque docs (#108)

(cherry picked from commit 7e147f1ddb8233964ff0981e6b64fc12edac99aa)

Doc/library/typing.rst

@@ -574,6 +574,8 @@ The module defines the following classes, functions and decorators:
 
    A generic version of :class:`collections.deque`.
 
+   .. versionadded:: 3.6.1
+
 .. class:: List(list, MutableSequence[T])
 
    Generic version of :class:`list`.