New wiki page content
<!-- learn react -->
----
<html>
<head>
<script src="https://unpkg.com/react@16/umd/react.development.js" crossorigin></script>
<script src="https://unpkg.com/react-dom@16/umd/react-dom.development.js" crossorigin></script>
<script src="https://unpkg.com/babel-standalone@6/babel.min.js"></script>
</head>
<body>
<div id="root"></div>
<script type="text/babel">
const clock = (
// 一个React DOM元素只能有一个根元素，因此
// <h1>和<p>必须用一个根元素包起来：
<div>
<h1>Clock</h1>
<p>It is { new Date().toLocaleString() }</p>
</div>
);
ReactDOM.render(
clock,
document.getElementById('root')
);
</script>
</body>
</html>
