Add Hugging Face example code and links to models and demos

[katielink]

Hello! I've added some code examples for usage with Hugging Face transformers as well as added links to the model checkpoints currently on the Hugging Face Hub. I've also included links to a couple demos.

By the way, it would be great to add the rest of the model checkpoints! Let me know if you'd be interested and I'd be happy to help with that.

[katielink]

@microsoft-github-policy-service agree company="Hugging Face"