Add cross-reference to the collections docs.

Doc/library/queue.rst

@@ -66,6 +66,12 @@ The :mod:`Queue` module defines the following classes and exceptions:
    Exception raised when non-blocking :meth:`put` (or :meth:`put_nowait`) is called
    on a :class:`Queue` object which is full.
 
+.. seealso::
+
+   :class:`collections.deque` is an alternative implementation of unbounded
+   queues with fast atomic :func:`append` and :func:`popleft` operations that
+   do not require locking.
+
 
 .. _queueobjects: