Sync classref with current source

classes/class_mutex.rst

@@ -34,6 +34,11 @@ Description
 
 A synchronization mutex (mutual exclusion). This is used to synchronize multiple :ref:`Thread<class_Thread>`\ s, and is equivalent to a binary :ref:`Semaphore<class_Semaphore>`. It guarantees that only one thread can ever acquire the lock at a time. A mutex can be used to protect a critical section; however, be careful to avoid deadlocks.
 
+Tutorials
+---------
+
+- :doc:`../tutorials/threads/using_multiple_threads`
+
 Method Descriptions
 -------------------