Open up SSH by default

modules/core/services.nix

@@ -4,7 +4,9 @@
   # For rage encryption, all hosts need a ssh key pair
   services.openssh = {
     enable = true;
-    openFirewall = lib.mkDefault false;
+    # If you don't want the host to have SSH actually opened up to the net,
+    # set `services.openssh.openFirewall` to false in your config.
+    openFirewall = lib.mkDefault true;
   };
 
   # Service that makes Out of Memory Killer more effective