message: use getAssetPath() for favicon and touch icon
diff: @@ -4,6 +4,7 @@ import Document, {Head, Main, NextScript} from 'next/document'
  import baseCSS from '../dist/primer-components.css'
  import {ServerStyleSheet} from 'styled-components'
  import {extractCritical} from 'emotion-server'
  +import {getAssetPath} from './doc-components'
  export default class MyDocument extends Document {
  static getInitialProps({renderPage}) {
  @@ -15,22 +16,15 @@ export default class MyDocument extends Document {
  }
  render() {
  - const {
  - css,
  - styles,
  - // the assetPrefix is set in next.config.js
  - __NEXT_DATA__: {assetPrefix = ''}
  - } = this.props
  -
  - const asset = path => assetPrefix + path
  + const {css, styles} = this.props
  return (
  <html lang="en">
  <Head>
  <title>Primer Components</title>
  <meta charSet="utf8" />
  - <link rel="icon" href={asset('/static/assets/favicon.png')} />
  - <link rel="apple-touch-icon" href={asset('/static/assets/apple-touch-icon.png')} />
  + <link rel="icon" href={getAssetPath('favicon.png')} />
  + <link rel="apple-touch-icon" href={getAssetPath('apple-touch-icon.png')} />
  <style id="primer-components">{baseCSS}</style>
  <style id="emotion-static">{css}</style>
  {styles}
  