Update how to guides

[stevhliu]

As discussed in #818, this PR de-emphasizes integrating download/upload functions into third-party libraries. The guides simply tell a user how to use these functions. We can follow this up with an integration guide that provides more value to library maintainers/developers who want to integrate these functions into their libraries. This PR also splits the old upstream utility doc into:

1. How to upload files (commit context manager, push_to_hub and Git LFS).
2. How to create and manage a repository (create_repo, delete_repo update_repo_visibility, the Repository class and its associated git-commands). This page is still a work in progress :)
3. Documents other Repository commands like pull, add, commit and push. I think it's nice for users to see they can manually do this if they want to instead of using the commit context manager or push_to_hub.
4. Rename some section headers so it's easier for users to find what they're looking for. Users might not know what snapshot_download is when they scan the headers.
5. Adds InferenceApi to the API Reference.

Something I would appreciate feedback on:

Do we still want to keep the list_model/dataset(filter=...) and model/dataset_info sections? It looks like you can do the same thing more efficiently with what is currently in the Searching the Hub doc.

To do:

• Finish doc on how to create and manage a repository.

[HuggingFaceDocBuilderDev]

The documentation is not available anymore as the PR was closed or merged.

[osanseviero]

This is super nice, I left some comments/suggestions

[LysandreJik]

Very nice! Thanks for working on this, @stevhliu

[adrinjalali]

Shouldn't this PR go to https://github.com/huggingface/hub-docs ?

[LysandreJik]

The guides that are affected here are guides related to the huggingface_hub client library, as can be seen here: https://huggingface.co/docs/huggingface_hub/index

The following PR #833 removed the guides that were unrelated to huggingface_hub as they're hosted in hub-docs.

It's the guides that are affected here should be removed from hub-docs IMO as they're currently duplicated (cc @osanseviero, happy to open a PR).

[osanseviero]

@LysandreJik with the docs revamp from @NimaBoscarino a significant part of it will be removed, I'm not sure if it's worth opening a PR for removing that as soon all of it will be removed/updated