Update ONNX docs (#23185)
Summary:
This is still work in progress.
There are several more items to add to complete this doc, including
- [x] LHS indexing, index assignments.
- [x] Tensor List.
- [x] ~Shape/Type propagation.~
- [x] FAQs
Please review and share your thoughts, feel free to add anything that you think should be included as well. houseroad spandantiwari lara-hdr neginraoof
Pull Request resolved: https://github.com/pytorch/pytorch/pull/23185
Differential Revision: D16459647
Pulled By: houseroad
fbshipit-source-id: b401c005f848d957541ba3b00e00c93ac2f4609b
