ajout d'une option dans tinc pour stocker le nom DNS de la machine

options.nix

@@ -77,6 +77,11 @@ let
 
       tinc = {
         enable = mkEnableOption "Enable tinc service";
+        dnsFQDN = mkOption {
+          example = "device.example.net.";
+          description = "DNS name of host pointing to tunnel IP.";
+          type = lib.types.string;
+        };
         connectToAddress = mkOption {
           default = "";
           example = "192.168.1.1";