docs: add banner for Angular AI developer event (angular#63734)

PR Close angular#63734

Author: thesmiler

adev/src/app/features/home/components/home-animation/home-animation.component.html

@@ -7,11 +7,11 @@
         class="adev-banner"
         target="_blank"
       >
-        <h1 tabindex="-1">Angular v20 is here!</h1>
-        <p class="adev-banner-cta">Read about our newest release</p>
+        <h1 tabindex="-1">Join us at the Angular AI Developer Event</h1>
+        <p class="adev-banner-cta">September 16, 2025 12 PM Eastern/9 AM Pacific</p>
       </a>
       <a
-        href="https://angular.dev/ai/develop-with-ai"
+        href="https://goo.gle/angular-ai-update"
         class="adev-banner"
         target="_blank"
       >