Update site from bootstrap 2.1.1 to 3.3.5

docs/templates/shared/_header.liquid

@@ -1,26 +1,28 @@
 
-<div class="navbar navbar-inverse navbar-fixed-top">
-  <div class="navbar-inner">
-    <div class="container">
-      <button type="button" class="btn btn-navbar" data-toggle="collapse" data-target=".nav-collapse">
+<div class="navbar navbar-default navbar-fixed-top">
+  <div class="container">
+    <div class="navbar-header">
+      <button aria-expanded="false" type="button" class="navbar-toggle collapsed" data-toggle="collapse" data-target="#nav-collapse">
+        <span class="sr-only">Toggle navigation</span>
         <span class="icon-bar"></span>
         <span class="icon-bar"></span>
         <span class="icon-bar"></span>
       </button>
-      <a class="brand" href="{{root}}/">jq</a>
-      <div class="nav-collapse collapse">
-        <ul class="nav">
-          {% for item in navigation %}
-            <li {% if item.permalink == permalink %} class="active" {% endif %}>
-              <a href="{{root}}{{item.permalink}}">{{item.name}}</a>
-            </li>
-          {% endfor %}
-          <li><a href="https://github.com/stedolan/jq/issues">Issues</a></li>
-          <li><a href="https://github.com/stedolan/jq">Source</a></li>
-          <li><a href="http://jqplay.org">Try online!</a></li>
-          <li><a href="https://raw.githubusercontent.com/stedolan/jq/master/NEWS">News</a></li>
-        </ul>
-      </div>
+      <a class="navbar-brand" href="{{root}}/">jq</a>
+    </div>
+
+    <div style="height: 1px;" aria-expanded="false" class="navbar-collapse collapse" id="nav-collapse">
+      <ul class="nav navbar-nav">
+        {% for item in navigation %}
+          <li {% if item.permalink == permalink %} class="active" {% endif %}>
+            <a href="{{root}}{{item.permalink}}">{{item.name}}</a>
+          </li>
+        {% endfor %}
+        <li><a href="https://github.com/stedolan/jq/issues">Issues</a></li>
+        <li><a href="https://github.com/stedolan/jq">Source</a></li>
+        <li><a href="http://jqplay.org">Try online!</a></li>
+        <li><a href="https://raw.githubusercontent.com/stedolan/jq/master/NEWS">News</a></li>
+      </ul>
     </div>
   </div>
 </div>