Update server-data.rst

Author: 94noni

frontend/encore/server-data.rst

@@ -22,6 +22,7 @@ Fetch this in JavaScript:
     document.addEventListener('DOMContentLoaded', function() {
         var userRating = document.querySelector('.js-user-rating');
         var isAuthenticated = userRating.dataset.isAuthenticated;
+        var user = JSON.parse(userRating.dataset.user);
 
         // or with jQuery
         //var isAuthenticated = $('.js-user-rating').data('isAuthenticated');