Add printer support.

This is cobbled together from several different forum posts and is
likely suboptimal. The avahi support made the system auto-discover the
printer, but it wasn't able to send data to the printer successfully.

nalai/configuration.nix

@@ -2,7 +2,7 @@
 # your system.  Help is available in the configuration.nix(5) man page
 # and in the NixOS manual (accessible by running ‘nixos-help’).
 
-{ config, pkgs, ... }:
+{ config, lib, pkgs, ... }:
 
 {
   imports =
@@ -107,6 +107,7 @@
   # $ nix search wget
   environment.systemPackages = with pkgs; [
     chezmoi
+    cups-filters
     dig
     fish
     gimp-with-plugins
@@ -129,6 +130,13 @@
 
   # Enable the OpenSSH daemon.
   # services.openssh.enable = true;
+  services.avahi = {
+    enable = true;
+    nssmdns4 = true;
+    publish.enable = true;
+    publish.workstation = true;
+    publish.addresses = true;
+  };
   services.tailscale.enable = true;
 
   # Open ports in the firewall.