message: wrap x0 app in an emotion-theming ThemeProvider
diff: import React from 'react'
  +import {ThemeProvider} from 'emotion-theming'
  import PropTypes from 'prop-types'
  import {NavLink} from 'react-router-dom'
  import Styles from './doc-components/Styles'
  import Octicon, {Package} from '@githubprimer/octicons-react'
  -import {Block, Link, Text, UnderlineNav, UnderlineNavLink} from '../src'
  +import {Block, Link, Text, UnderlineNav, UnderlineNavLink, theme} from '../src'
  import {name, repository, version} from '../package.json'
  const pkg = `${name}@${version}`
  @@ -13,6 +14,7 @@ export default function Page({render}) {
  return (
  <React.Fragment>
  <Styles />
  + <ThemeProvider theme={theme}>
  <div className="text-dark-gray">
  <UnderlineNav
  actions={
  @@ -34,6 +36,7 @@ export default function Page({render}) {
  </UnderlineNav>
  <Block p={3}>{render()}</Block>
  </div>
  + </ThemeProvider>
  </React.Fragment>
  )
  }
  