Support running private models with community inference API

[lewtun]

As a user it would be nice to use the inference API widgets for private models generated via one of the Docker images in api-inference-community.

Here's an example model repo and a screenshot of the widget message.

[osanseviero]

Related: huggingface/api-inference-community#26 and huggingface/api-inference-community#26.

As far as I know, community libraries do not support private repos by design, but I don't see any very strong reason to not have private repos.