title: How set up a Gatsby Cookie consent banner with gatsby-plugin-gdpr-cookies
body: <p>My website gathers information for Google Analytics, so I need to include a Cookie consent banner for the users to opt in/out of. </p>
  
  <p>I saw the plugin <code>gatsby-plugin-gdpr-cookies</code> and thought it looked perfect. 
  I've followed the startup and have it inside my config file. However I'm not sure what to do next. Do I need to create a banner component and link it all up somehow? I've tried to look around for other examples but can't see any. </p>
  
  <p>Any help appreciated, thanks.</p>