add timeout newsletter banner delay 10s

layouts/partials/newsletter.html

@@ -109,9 +109,11 @@
         }
 
         window.onload = function() {
+            setTimeout(function() {
                 if (!getCookie('bannerClosed')) {
                     document.getElementById('modern-banner').style.display = 'block';
                 }
+            }, 10000); // 15000 milliseconds = 15 seconds
         }
     </script>
 </body>