Encode revision in remote URL

[xenova]

Required to support accessing PRs on the HF Hub. e.g.,

const pipe = await pipeline('task', 'model', {
   revision: 'refs/pr/1', // Access files from PR
});

[HuggingFaceDocBuilderDev]

The docs for this PR live here. All of your documentation changes will be reflected on that endpoint. The docs are available until 30 days after the last update.