update demo pages

demo/pages/_app.js

@@ -1,12 +1,6 @@
 import 'tailwindcss/tailwind.css'
 import React from 'react'
-import App from 'next/app'
 
-class MyApp extends App {
-  render() {
-    const { Component, pageProps } = this.props
-    return <Component {...pageProps} />
-  }
+export default function App({ Component, pageProps }) {
+  return <Component {...pageProps} />
 }
-
-export default MyApp