Remove wrong role="tabpanel" from parent container

As per discussion on https://github.com/w3c/wai-wcag-quickref/issues/2
and #13554

docs/_includes/js/tabs.html

@@ -3,7 +3,7 @@
 
   <h2 id="tabs-examples">Example tabs</h2>
   <p>Add quick, dynamic tab functionality to transition through panes of local content, even via dropdown menus.</p>
-  <div class="bs-example bs-example-tabs" role="tabpanel" data-example-id="togglable-tabs">
+  <div class="bs-example bs-example-tabs" data-example-id="togglable-tabs">
     <ul id="myTabs" class="nav nav-tabs" role="tablist">
       <li role="presentation" class="active"><a href="#home" id="home-tab" role="tab" data-toggle="tab" aria-controls="home" aria-expanded="true">Home</a></li>
       <li role="presentation"><a href="#profile" role="tab" id="profile-tab" data-toggle="tab" aria-controls="profile">Profile</a></li>
@@ -59,7 +59,7 @@ $('#myTabs li:eq(2) a').tab('show') // Select third tab (0-indexed)
   <h3>Markup</h3>
   <p>You can activate a tab or pill navigation without writing any JavaScript by simply specifying <code>data-toggle="tab"</code> or <code>data-toggle="pill"</code> on an element. Adding the <code>nav</code> and <code>nav-tabs</code> classes to the tab <code>ul</code> will apply the Bootstrap <a href="../components/#nav-tabs">tab styling</a>, while adding the <code>nav</code> and <code>nav-pills</code> classes will apply <a href="../components/#nav-pills">pill styling</a>.</p>
 {% highlight html %}
-<div role="tabpanel">
+<div>
 
   <!-- Nav tabs -->
   <ul class="nav nav-tabs" role="tablist">