message: Added output
  Added an input to train the model on and the output it returns
diff: @@ -373,10 +373,15 @@ class MaxPooling2D(Pooling2D):
  Usage Example:
  + >>> input_image = np.random.normal(0.5,0.1,(1,28,28,1))
  + >>> output = np.random.normal(0.5,0.1,(1,13,13,16))
  >>> model = tf.keras.models.Sequential()
  - >>> model.add(tf.keras.layers.Conv2D(32, kernel_size=(3, 3),
  + >>> model.add(tf.keras.layers.Conv2D(16, kernel_size=(3, 3),
  ... input_shape=(28,28,1)))
  >>> model.add(tf.keras.layers.MaxPooling2D(pool_size=(2, 2)))
  + >>> model.compile('adam', 'mean_squared_error')
  + >>> model.fit(input_image, output)
  + <tensorflow.python.keras.callbacks.History at 0x7f851d526e48>
  For example, for stride=(1,1) and padding="same":
  