Show only dc version in the navbar

Author: kum-deepak

_includes/examples-header.html

@@ -27,6 +27,6 @@
 
 <script type="application/javascript">
   document.addEventListener("DOMContentLoaded", () => {
-    d3.select('#versions').text(`dc.js: ${dc.version}, d3: ${d3.version}`);
+    d3.select('#versions').text(`dc.js: ${dc.version}`);
   });
 </script>