nix-pre-commit v0.1

First version of nix-pre-commit.

Includes the mkDevShell utility:

devShell."x86_64-linux" = pre-commit-env."x86_64-linux".mkDevShell {
  extraPackages = with pkgs; [
    # Add any extra packages you need here
  ];
  extraShellHook = ''
    # Add any extra shell commands you want to run here
  '';
};