old_contents: import React from 'react';
  
  
  class MainNavigation extends React.Component {
  	render() {
  		return (
  			<div>
  			</div>
  		);
  	}
  }
  
  
  export default MainNavigation;
  
new_contents: import React from 'react';
  import { Link } from 'react-router-dom';
  
  
  const linkStyle = 'pt-button pt-minimal';
  
  class MainNavigation extends React.Component {
  
  	render() {
  		return (
  			<div>
  				<a className={linkStyle + ' pt-icon pt-icon-key-escape'} href='/'>Visit site</a>
  			</div>
  		);
  	}
  }
  
  
  export default MainNavigation;
  
subject: Add visit site link to navbar