Is your feature request related to a problem? Please describe.

Saw some unproductive comments about formatting today. Nothing too bad, but we could prevent this.

Describe the solution you'd like

• nixpkgs-fmt
• pre-commit-hooks.nix configuration that installs the hook in shellHook
• .git-blame-ignore-revs file, now also supported by GitHub web app

Describe alternatives you've considered

Carry on.

Additional context

I think we can just vote among the Nix Team and I'll be happy either way.

Priorities

Add 👍 to issues you find important.