Add stanford dog dataset
_The documentation is not available anymore as the PR was closed or merged._ Hi @khushmeeet, thanks for your contribution.

But wouldn't it be better to add this dataset to the Hub? 
- https://huggingface.co/docs/datasets/share
- https://huggingface.co/docs/datasets/dataset_script Hi @albertvillanova 

Dataset is added to Hub - https://huggingface.co/datasets/dgrnd4/stanford_dog_dataset Great, so I guess we can close this issue, as the dataset is already available on the Hub. OK I read the discussion on:
- #4504

Currently, priority is adding datasets to the Hub, not here on GitHub.

If you would like to contribute the loading script and all the metadata you generated (README + JSON files), you could:
- Either make a PR to the existing dataset on the Hub
- Create a new dataset on the Hub:
  - Either under your personal namespace
  - or even more professionally, under the namespace `stanfordSVL` (Stanford Vision and Learning Lab: https://svl.stanford.edu/)

You can use the Community tab to ping us if you need help or have any questions.
This PR is for adding dataset, related to issue #4504.

We are adding Stanford dog breed dataset. It is a multi class image classification dataset. 
Details can be found here - http://vision.stanford.edu/aditya86/ImageNetDogs/

Tests on dummy data is failing currently, which I am looking into.