Add HuggingFace Hub integration.

[shivakanthsujit]

Types of changes

Add helper utils to

• upload models to HuggingFace Hub along with auto generating model metadata (optionally agent performance and evaluation video )
• download model params, environment normalizers from repo to pass to Model.load()

• Docs change / refactoring / dependency upgrade
• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to change)

Motivation and Context / Related issue

#169

Checklist

• The documentation is up-to-date with the changes I made.
• I have read the CONTRIBUTING document and completed the CLA (see CONTRIBUTING).
• All tests passed, and additional code has been covered with new tests.

[natolambert]

@luisenp it would be useful if you can enable the workflow :)

[natolambert]

Link to colab is here

I created a hub org where we can put some models for testing / benchmarks here.