update from render to createRoot and font import statement

frontend/index.tsx

@@ -1,22 +1,17 @@
 import React from 'react';
-import { render } from 'react-dom';
-// import { createRoot } from 'react-dom/client';
+// import { render } from 'react-dom';
+import { createRoot } from 'react-dom/client';
 
 import App from './components/App';
 // import 'codemirror/lib/codemirror.css';
 
-import 'fontsource-roboto';
+import '@fontsource/roboto';
 
-const root = document.createElement('div');
+const root = createRoot(document.createElement('div'));
 root.id = 'root';
 document.body.appendChild(root);
 
-render(
-  <div>
-    <App />
-  </div>,
-  document.getElementById('root'),
-);
+root.render(<App />);
 
 // const container = document.getElementById('root') as HTMLElement;
 // const root = createRoot(container);