Give hash in commit messages in doc push scripts (#47694)
Summary:
This PR replaces the current auto-generated commit messages like pytorch/pytorch.github.io@fb217ab34abee258575613b13641939eca1b0fe1 (currently includes no information) and pytorch/cppdocs@7efd67e8f1ff6a599f0870785a1540efa515970a (currently includes only a timestamp, which is redundant since it's a Git commit) with more descriptive ones that specify the pytorch/pytorch commit they originated from. This information would be useful for debugging issues such as https://github.com/pytorch/pytorch/issues/47462.
GitHub will also [autolink](https://docs.github.com/en/free-pro-team@latest/github/writing-on-github/autolinked-references-and-urls#commit-shas) these new messages (similar to ezyang/pytorch-ci-hud@bc25ae770d1088629fa17f5a5ce34aa94ce173e6), and so they will now also mostly follow Git commit message conventions by starting with a capital letter, using the imperative voice, and (at least in the autolink-rendered form on GitHub, although not in the raw text) staying under 50 characters.
**Question for reviewers:** Will my `export CIRCLE_SHA1="$CIRCLE_SHA1"` work here? Is it necessary?
Pull Request resolved: https://github.com/pytorch/pytorch/pull/47694
Reviewed By: walterddr
Differential Revision: D24868240
Pulled By: samestep
fbshipit-source-id: 4907341e7b57ed6818ab550dc1ec423f2c2450c1
