message: Improve tf.make_ndarray() docstring
  Added a usage example to improve documentation.
diff: @@ -565,6 +565,17 @@ def MakeNdarray(tensor):
  Create a numpy ndarray with the same shape and data as the tensor.
  + For example:
  +
  + ```python
  + # Tensor a has shape (2,3)
  + a = tf.constant([[1,2,3],[4,5,6]])
  + proto_tensor = tf.make_tensor_proto(a) # convert `tensor a` to a proto tensor
  + tf.make_ndarray(proto_tensor) # output: array([[1, 2, 3],
  + # [4, 5, 6]], dtype=int32)
  + # output has shape (2,3)
  + ```
  +
  Args:
  tensor: A TensorProto.
  