message: add primer-react@version link to main nav
diff: @@ -2,14 +2,24 @@ import React from 'react'
  import PropTypes from 'prop-types'
  import {NavLink} from 'react-router-dom'
  import Styles from './doc-components/Styles'
  -import {UnderlineNav, UnderlineNavItem} from '../src'
  +import Octicon, {Package} from '@github/octicons-react'
  +import {Block, Link, Text, UnderlineNav, UnderlineNavItem} from '../src'
  +import {name, repository, version} from '../package.json'
  +
  +const pkg = `${name}@${version}`
  +const releaseURL = `https://github.com/${repository}/releases/v${version}`
  export default function Page({render}) {
  return (
  <React.Fragment>
  <Styles />
  <div className="text-dark-gray">
  - <UnderlineNav>
  + <UnderlineNav actions={(
  + <Text color="gray-light" mono px={4}>
  + <Octicon icon={Package} className="mr-2" />
  + <Link href={releaseURL}>{pkg}</Link>
  + </Text>
  + )}>
  <UnderlineNavItem tag={NavLink} to="/components">
  Components
  </UnderlineNavItem>
  