(torchelastic) make --max_restarts explicit in the quickstart and runner docs (#65838)
Summary:
Pull Request resolved: https://github.com/pytorch/pytorch/pull/65838
closes https://github.com/pytorch/pytorch/pull/65675
The default `--max_restarts` for `torch.distributed.run` was changed to `0` from `3` to make things backwards compatible with `torch.distributed.launch`. Since the default `--max_restarts` used to be greater than `0` we never documented passing `--max_restarts` explicitly in any of our example code.
Test Plan: N/A doc change only
Reviewed By: d4l3k
Differential Revision: D31279544
fbshipit-source-id: 98b31e6a158371bc56907552c5c13958446716f9
