add channel patch example

flake.nix

@@ -26,6 +26,16 @@
 
     supportedSystems = [ "x86_64-linux" ];
 
+    # Patch example
+
+    # channels.nixpkgs-unstable.patches = [
+    #   (nixpkgs-unstable.legacyPackages."x86_64-linux".fetchpatch {
+    #     name = "electron-cash.patch";
+    #     url = "https://github.com/NixOS/nixpkgs/pull/160607.patch";
+    #     sha256 = "sha256-oQbiyhVWYIkEuZEKqaPuIL00PNPnuTAw64wuqZ8YeDs=";
+    #   })
+    # ];
+
     hostDefaults.modules = [
       nixpkgs.nixosModules.notDetected
       {

systems/PC-Fixe/configuration.nix

@@ -212,6 +212,9 @@
     Option "metamodes" "DP-4: 3440x1440_144 +0+0 {AllowGSYNCCompatible=On}"
   '';
 
+  services.printing.enable = true;
+  services.printing.drivers = [ pkgs.hplip ];
+
   systemd = let
     DP4Config = "--output DP-4 --mode 3440x1440 --rate 144";
     HDMIConfig = "--output HDMI-0 --auto --left-of DP-4";