Update CRA template for v5. (#7312)

examples/create-react-app/src/App.js

@@ -1,56 +1,24 @@
-import React from 'react';
-import { useEffect, useState } from 'react';
+import logo from './logo.svg';
 import './App.css';
 
 function App() {
-  const [date, setDate] = useState(null);
-  useEffect(() => {
-    async function getDate() {
-      const res = await fetch('/api/date');
-      const newDate = await res.text();
-      setDate(newDate);
-    }
-    getDate();
-  }, []);
   return (
-    <main>
-      <h1>Create React App + Go API</h1>
-      <h2>
-        Deployed with{' '}
+    <div className="App">
+      <header className="App-header">
+        <img src={logo} className="App-logo" alt="logo" />
+        <p>
+          Edit <code>src/App.js</code> and save to reload.
+        </p>
         <a
-          href="https://vercel.com/docs"
+          className="App-link"
+          href="https://reactjs.org"
           target="_blank"
-          rel="noreferrer noopener"
+          rel="noopener noreferrer"
         >
-          Vercel
+          Learn React
         </a>
-        !
-      </h2>
-      <p>
-        <a
-          href="https://github.com/vercel/vercel/tree/main/examples/create-react-app"
-          target="_blank"
-          rel="noreferrer noopener"
-        >
-          This project
-        </a>{' '}
-        was bootstrapped with{' '}
-        <a href="https://facebook.github.io/create-react-app/">
-          Create React App
-        </a>{' '}
-        and contains three directories, <code>/public</code> for static assets,{' '}
-        <code>/src</code> for components and content, and <code>/api</code>{' '}
-        which contains a serverless <a href="https://golang.org/">Go</a>{' '}
-        function. See{' '}
-        <a href="/api/date">
-          <code>api/date</code> for the Date API with Go
-        </a>
-        .
-      </p>
-      <br />
-      <h2>The date according to Go is:</h2>
-      <p>{date ? date : 'Loading date...'}</p>
-    </main>
+      </header>
+    </div>
   );
 }