Document how to deploy to Hugging Face Spaces

[jtpio]

Problem

Hugging Face, via its Spaces, provides a convenient way to deploy Voila apps for free by pushing to a repo (similar to Heroku).

They also have a generous free tier: https://huggingface.co/docs/hub/spaces-overview#hardware-resources

Suggested Improvement

Add a section to the documentation to show how to deploy to Hugging Face Spaces: https://voila.readthedocs.io/en/stable/deploy.html#cloud-service-providers

We could also create https://github.com/voila-dashboards/voila-huggingface and have an example automatically deployed to HuggingFace Spaces via CI.

[jtpio]

automatically deployed to HuggingFace Spaces via CI.

I created the voila-dashboards organization on Hugging Face where we could deploy such example application: https://huggingface.co/voila-dashboards

[jtpio]

create https://github.com/voila-dashboards/voila-huggingface

This could be bootstrapped from https://github.com/opengeos/voila-geospatial (tracked in opengeos/voila-geospatial#1) which is already a good example.