message: Update docstring for keras.layers.InputLayer.
diff: @@ -41,22 +41,48 @@ class InputLayer(base_layer.Layer):
  It is generally recommend to use the functional layer API via `Input`,
  (which creates an `InputLayer`) without directly using `InputLayer`.
  + When using InputLayer with Keras Sequential model, it can be skipped by
  + moving the input_shape parameter to the first layer after the InputLayer.
  +
  This class can create placeholders for tf.Tensors, tf.SparseTensors, and
  - tf.RaggedTensors by choosing 'sparse=True' or 'ragged=True'.
  + tf.RaggedTensors by choosing 'sparse=True' or 'ragged=True'. Note that
  + 'sparse' and 'ragged' can't be configured to True at same time.
  + Usage:
  +
  + ```python
  + # With explicit InputLayer.
  + model = tf.keras.Sequential([
  + tf.keras.layers.InputLayer(input_shape=(4,)),
  + tf.keras.layers.Dense(8)])
  + model.compile(tf.optimizers.RMSprop(0.001), loss='mse')
  + model.fit(np.zeros((10, 4)),
  + np.ones((10, 8)))
  +
  + # Without InputLayer and let the first layer to have the input_shape.
  + # Keras will add a input for the model behind the scene.
  + model = tf.keras.Sequential([
  + tf.keras.layers.Dense(8, input_shape=(4,))])
  + model.compile(tf.optimizers.RMSprop(0.001), loss='mse')
  + model.fit(np.zeros((10, 4)),
  + np.ones((10, 8)))
  + ```
  Arguments:
  input_shape: Shape tuple (not including the batch axis), or `TensorShape`
  instance (not including the batch axis).
  batch_size: Optional input batch size (integer or None).
  - dtype: Datatype of the input.
  + dtype: Optional datatype of the input. When not provided, the Keras
  + default float type will be used.
  input_tensor: Optional tensor to use as layer input
  instead of creating a placeholder.
  sparse: Boolean, whether the placeholder created is meant to be sparse.
  + Default to False.
  ragged: Boolean, whether the placeholder created is meant to be ragged.
  In this case, values of 'None' in the 'shape' argument represent
  ragged dimensions. For more information about RaggedTensors, see
  https://www.tensorflow.org/guide/ragged_tensors.
  - name: Name of the layer (string).
  + Default to False.
  + name: Optional name of the layer (string).
  """
  def __init__(self,
  