message: Add Examples to MobileNetV2
diff: @@ -163,6 +163,33 @@ def MobileNetV2(input_shape=None,
  Returns:
  A `keras.Model` instance.
  + Example:
  +
  + ```python
  + #Extract image features with MobileNetV2-224
  + from tensorflow.keras.applications.mobilenet_v2 import MobileNetV2
  + from tensorflow.keras.preprocessing import image
  + from tensorflow.keras.applications.mobilenet_v2 import preprocess_input
  + import numpy as np
  +
  + #create a MobileNetV2 model pre-trained on imagenet
  + model = MobileNetV2(weights='imagenet', include_top=False, input_shape=[224,224,3])
  +
  + #process the input
  + img_path = 'elephant_example.jpg'
  + img = image.load_img(img_path, target_size=(224, 224))
  + x = image.img_to_array(img)
  + x = np.expand_dims(x, axis=0)
  + x = preprocess_input(x)
  +
  + #extract the features
  + features = model.predict(x)
  + ```
  +
  + >>>model = MobileNetV2(weights = None, input_shape=[224,224,3])
  + >>>model.name
  + 'mobilenetv2_1.00_224'
  +
  Raises:
  ValueError: in case of invalid argument for `weights`,
  or invalid input shape or invalid alpha, rows when
  