Add an example notebook for image classification

[yashk2000]

Training models in the project is done using Google Cloud Vision. In order to make full use of this, a contributor should also understand how the training procedure actually works.

I will put an example notebook that is trained on a dataset of 5 categories of flowers along with a detailed explanation of what is happening.

I will use feature extraction and fine-tuning methods on the VGG19 network and the DenseNet network pre-trained on the ImageNet dataset.