change the documentation menu link from toc to index

Change-Id: Icec2ea5c174f9dda43291ccadc0321aab2088ced
(cherry picked from commit d1b3f333c2)

_templates/mirantis/static/abtest.js

@@ -246,6 +246,8 @@ $(document).ready(function () {
 
 	$('a.toc-backref').contents().unwrap();
 
+	$('ul.nav.navbar-nav > li > a[href="contents.html"]').attr('href', 'index.html');
+
 	prepareList();
 
 });