message: remove unecessary extract critical
diff: import React from 'react'
  import Document, {Main, NextScript} from 'next/document'
  import {ServerStyleSheet} from 'styled-components'
  -import {extractCritical} from 'emotion-server'
  import {getAssetPath} from './doc-components'
  import {utilities, markdown} from '../css'
  @@ -17,7 +16,6 @@ export default class MyDocument extends Document {
  {utilities}
  {markdown}
  </style>
  - <style id="emotion-static">{extractCritical(page.html).css}</style>
  {sheet.getStyleElement()}
  </>
  )
  