title: Moodle 3.3 - check if a user is authenticated in Mustache template
body: <p>I'm creating a mustache template for a Moodle site and want to display some content on the front page but only if the user is not yet logged in. I was hoping I could do something like this in the template: </p>
  
  <p><code>{{^usernotloggedin}}
      My content for users not logged in.
  {{/usernotloggedin}}</code></p>
  
  <p>However I can't find any documentation on the user variables available to mustache to test if a user is authenticated or not.</p>
  
  <p>Any advice of where to look or how to implement this would be great.</p>