Added Search function for items and fixed javascript controller

app/javascript/controllers/search_form_controller.js

@@ -0,0 +1,11 @@
+import { Controller } from "@hotwired/stimulus";
+
+export default class extends Controller {
+  submit() {
+    clearTimeout(this.timeout);
+    // Wartet 200ms nach dem letzten Tastendruck, bevor gesucht wird
+    this.timeout = setTimeout(() => {
+      this.element.requestSubmit();
+    }, 200);
+  }
+}