Motivation for this change

A true hacker requires a transparent terminal ;)

Furthermore I'd love to have this configurable using the services.compton module.

To test the change I built the following test VM:

{
  compton = { pkgs, ... }: {
    users.extraUsers.vm = {
      isNormalUser = true;
      password = "vm";
    };
    environment.systemPackages = [ pkgs.google-chrome ];
    services.xserver = {
      enable = true;
      windowManager.i3.enable = true;
      windowManager.default = "i3";
    };
    services.compton = {
      enable = true;
      opacityRules = [ "70:class_g = 'Google-chrome'" ];
    };
    nixpkgs.config.allowUnfree = true;
  };
}

This makes google-chrome transparent in the VM.

Things done

• Tested using sandboxing (nix.useSandbox on NixOS, or option build-use-sandbox in nix.conf on non-NixOS)
• Built on platform(s)
  • NixOS
  • macOS
  • other Linux distributions
• Tested via one or more NixOS test(s) if existing and applicable for the change (look inside nixos/tests)
• Tested compilation of all pkgs that depend on this change using nix-shell -p nox --run "nox-review wip"
• Tested execution of all binary files (usually in ./result/bin/)
• Fits CONTRIBUTING.md.