Update tutorial-define-gateway-device-type.md

Adding a note to call out that "VSCode based code generation is currently not supported for gateway devices modeled in IoT Central. "

Author: sandeeppujar

articles/iot-central/core/tutorial-define-gateway-device-type.md

@@ -199,6 +199,9 @@ In this tutorial, you learned how to:
 * Add relationships.
 * Publish your device template.
 
+> [!NOTE]
+> VSCode based code generation is currently not supported for gateway devices modeled in IoT Central. 
+
 Next, you can:
 
 > [!div class="nextstepaction"]