Use overlay

Signed-off-by: Nikolaos Karaolidis <nick@karaolidis.com>

scripts/add-host.sh

@@ -162,6 +162,12 @@ EOF
 cat <<EOF > "./hosts/$host/default.nix"
 { inputs, ... }:
 {
+  nixpkgs.overlays = [
+    inputs.lib.overlays.default
+    inputs.self.overlays.default
+    inputs.nur.overlays.default
+  ];
+
   imports = [
     inputs.disko.nixosModules.disko
     ./format.nix