Summary:
This changes the link for installing binaries to the page on pytorch.org that is entirely the download command selector (which isn't visible on a normal aspect ratio screen when the main website page first loads anymore).

This also includes some other random fixes:
* Update HUD link
* Clean ups

Fixes #{issue number}

Pull Request resolved: https://github.com/pytorch/pytorch/pull/66828

Reviewed By: malfet

Differential Revision: D31750654

Pulled By: driazati

fbshipit-source-id: aef9ceba71418f6f7648eab9a8c8a78d6c60518b