make typescript compilation work

client/src/index.js

@@ -1,11 +0,0 @@
-import React from 'react'
-import { createRoot } from 'react-dom/client';
-import './index.css';
-import App from './App';
-
-self.$RefreshReg$ = () => {};
-self.$RefreshSig$ = () => () => {};
-
-const container = document.getElementById('root');
-const root = createRoot(container); // createRoot(container!) if you use TypeScript
-root.render(<App />);

client/src/index.tsx

@@ -0,0 +1,8 @@
+import * as React from 'react';
+import { createRoot } from 'react-dom/client';
+import './index.css';
+import App from './App';
+
+const container = document.getElementById('root');
+const root = createRoot(container!);
+root.render(<App />);