message: Added description for call() in tf.keras.layers.Layer
diff: @@ -405,7 +405,11 @@ class Layer(module.Module, version_utils.LayerVersionSelector):
  @doc_controls.for_subclass_implementers
  def call(self, inputs, **kwargs): # pylint: disable=unused-argument
  - """This is where the layer's logic lives.
  + """This is where the layer's logic lives. The second parameter `kwargs`
  + is not used anywhere as of now. Note here that `call()` method in
  + `tf.keras` is little bit different from `keras` API. In `keras` API,
  + you can pass support masking for layers as additional arguements.
  + Whereas `tf.keras` has `compute_mask()` method to support masking.
  Arguments:
  inputs: Input tensor, or list/tuple of input tensors.
  