Organize Hub Xet docs (#1969)
* Reorganized Xet docs, hopefully this renders ok
* Add xet protocol subsection pages, finish toctree
* Fix links in xet proto contents pages
* quick fixes of some links
* Reorganize Storage Backend docs
* Fix TOC and link to xet protocol
* Fix storage-backends rename
* Update xet protocol to 1.0.0
* add xet protocol link to security
* Update docs/hub/_redirects.yml
add redirect for old storage-backends links
Co-authored-by: Julien Chaumond <julien@huggingface.co>
* Reorganizing TOC
* PR feedback
---------
Co-authored-by: Jared Sulzdorf <j.sulzdorf@gmail.com>
Co-authored-by: Julien Chaumond <julien@huggingface.co>
