Updated symfony recipes.

assets/controllers/hello_controller.js

@@ -0,0 +1,16 @@
+import { Controller } from 'stimulus';
+
+/*
+ * This is an example Stimulus controller!
+ *
+ * Any element with a data-controller="hello" attribute will cause
+ * this controller to be executed. The name "hello" comes from the filename:
+ * hello_controller.js -> "hello"
+ *
+ * Delete this file or adapt it for your use!
+ */
+export default class extends Controller {
+    connect() {
+        this.element.textContent = 'Hello Stimulus! Edit me in assets/controllers/hello_controller.js';
+    }
+}