Setting rev: master is no longer supported

[ofersadan85]

Following the readme in this repo, I get the following error:

The 'rev' field of repo 'https://github.com/doublify/pre-commit-rust' appears to be a mutable reference (moving tag / branch). Mutable references are never updated after first install and are not supported. See https://pre-commit.com/#using-the-latest-version-for-a-repository for more details. Hint: pre-commit autoupdate often fixes this.

Doing the recommended step fixes this:

pre-commit autoupdate

Which sets the hook to rev: v1.0 so I guess the readme needs to be updated to include this?