[ONNX] Update ONNX landing page since 1.3 (#32805)
Summary:
* New ops supported for exporting.
* Updates on support for tensor indexing and dynamic list of tensors.
* lara-hdr, spandantiwari Should we also include updates on torchvision support in this page?
cc houseroad, neginraoof Please review if I have missed anything.
Pull Request resolved: https://github.com/pytorch/pytorch/pull/32805
Reviewed By: hl475
Differential Revision: D19635699
Pulled By: houseroad
fbshipit-source-id: b6be4fce641f852dcbceed20b4433f4037d8024a
