update for webinar promo (#1693)

Author: Rob Lauer

build/_layouts/index.html

@@ -48,9 +48,11 @@
         <!-- Banner for promoting events -->
         <header class="ns-tip-container">
             <div>
+                🥳 NativeScript 6.0 is almost here! 
+                <a href="https://attendee.gotowebinar.com/register/5579493045301682178?source=yellow-strip-docs" target="_blank">Learn all about it at our launch webinar.</a>
+                <!--
                 🐦 Grab your early bird tickets for the next NativeScript conference!
                 <a href="https://jsmobileconf.com/" target="_blank">jsMobileConf is coming back to Boston.</a>
-                <!--
                 Looking for some inspiration? 💡
                 <a href="https://market.nativescript.org/?tab=samples&framework=all_frameworks&category=all_samples" target="_blank">Check out the new sample apps on the Marketplace!</a>
                 -->