Add basic datasets

[t-rutten]

We'd like to add datasets like those available through PyTorch, Tensorflow, Hugging Face, and scikit-learn. Here's a non-comprehensive list to get started:

Text

• IMDB reviews
• WMT translation
• Yelp reviews
• SQuAD

Vision

• Caltech 101
• CelebA
• ImageNet
• KMNIST
• Cityscapes

Misc.

• Iris
• Wine recognition
• Generated datasets (see scikit-learn)