[Beta] Add missing dependencies (#5220)

Author: holazz

beta/src/content/learn/separating-events-from-effects.md

@@ -796,6 +796,22 @@ With `useEvent`, there is no need to "lie" to the linter, and the code works as
 
 <Sandpack>
 
+```json package.json hidden
+{
+  "dependencies": {
+    "react": "experimental",
+    "react-dom": "experimental",
+    "react-scripts": "latest"
+  },
+  "scripts": {
+    "start": "react-scripts start",
+    "build": "react-scripts build",
+    "test": "react-scripts test --env=jsdom",
+    "eject": "react-scripts eject"
+  }
+}
+```
+
 ```js
 import { useState, useEffect } from 'react';
 import { experimental_useEvent as useEvent } from 'react';