minor wording change

docs/Using-TensorFlow-Sharp-in-Unity.md

 
 ![Internal Brain Inspector](images/internal_brain.png)
 
-See [Internal Brain](Learning-Environments-Design-External-Internal-Brains.md#internal-brain) for more information about using the Internal Brains.
+See [Internal Brain](Learning-Environments-Design-External-Internal-Brains.md#internal-brain) for more information about using Internal Brains.
 
 If you followed these instructions well, the agents in your environment that use this brain will use your fully trained network to make decisions.