add i3lock to sys config

sys/modules/yubikey.nix

@@ -25,6 +25,8 @@ in {
       enableSSHSupport = true;
     };
 
+    programs.i3lock.u2fSupport = true;
+
     security.pam = {
       services = {
         login.u2fAuth = true;

sys/platforms/posixlycorrect/default.nix

@@ -30,6 +30,8 @@
     };
   };
 
+  programs.i3lock.enable = true;
+
   networking = {
     hostName = "posixlycorrect";
     networkmanager.enable = true;