Update Next.js example to have css.resolve and server-side rendering working

[message]

Currently with-styled-jsx example is pretty basic and doesn't cover css.resolve and server-side rendering.

Examples like this doesn't work:

import React from 'react';
import css from 'styled-jsx/css';

export default function Home() {
	const {className, styles} = css.resolve`
		p { background: #000; color: green; font-weight: 700};
	`;

	const content = <div>
		<p>Test</p>
	</div>;

	return <div>
		<div className={className}>{content}</div>
		{styles}
	</div>
}