feat: install cups and avahi on alice

hosts/alice/default.nix

@@ -18,6 +18,7 @@
     ./gpg.nix
     ./keyd.nix
     ./pipewire.nix
+    ./printer.nix
     ./sway.nix
     ./tlp.nix
 

hosts/alice/printer.nix

@@ -0,0 +1,16 @@
+{pkgs, ...}: {
+  services = {
+    printing = {
+      enable = true;
+      drivers = with pkgs; [
+        hplip
+      ];
+    };
+
+    avahi = {
+      enable = true;
+      nssmdns = true;
+      openFirewall = true;
+    };
+  };
+}