chore: update banner styling

Author: rigor789

layouts/_partials/header.ejs

@@ -1,7 +1,7 @@
 <a href="https://www.surveymonkey.com/r/6FYQDZY?ref=nativescript-vue"
    target="_blank"
    rel="noopener"
-   class="block bg-blue-light md:bg-green md:border-t-8 border-green p-4 md:p-0 text-center no-underline text-white">
+   class="block bg-blue-light md:bg-green md:border-t-8 border-green p-4 md:p-0 text-center underline text-white">
    Help us improve NativeScript by filling out a quick survey!
 </a>
 <!--