message: import primer-utilities in the docs
diff: import React from 'react'
  import App, {Container} from 'next/app'
  import {Layout} from 'mdx-docs'
  +import {injectGlobal} from 'emotion'
  import Octicon, {iconsByName} from '@githubprimer/octicons-react'
  import * as primerComponents from '../src'
  import * as docComponents from './doc-components'
  +injectGlobal(preval`
  + const render = require('../lib/render-sass')
  + module.exports = render('@import "primer-utilities/index.scss";')
  +`)
  +
  const {SideNav, Header, IndexHero, customTheme} = docComponents
  const {Box, FlexContainer, Link} = primerComponents
  