Fix syntax error in index.js by adding a missing comma

Author: BilgeGates

src/index.js

@@ -7,5 +7,5 @@ const root = ReactDOM.createRoot(document.getElementById("root"));
 root.render(
   <React.StrictMode>
     <App />
-  </React.StrictMode>
+  </React.StrictMode>,
 );