First draft of 'under construction' alert

layouts/partials/banner.html

@@ -46,3 +46,11 @@
     </div>
   </div>
 </section>
+<div class="usa-alert usa-alert--info margin-top-0">
+  <div class="usa-alert__body">
+    <p class="usa-alert__heading"><b>We’re working on a new version of Tech at GSA.</b></p>
+    <p class="usa-alert__text">
+      We’re adding tools to help GSA <a href="https://www.whitehouse.gov/omb/management/ofcio/delivering-a-digital-first-public-experience/">deliver a digital-first public experience.</a> You can track our progress in <a href="https://github.com/GSA/cto-website">our open-source repository</a>.
+    </p>
+  </div>
+</div>