#1: Add Bootstrap aria tags to nav button

Author: adielcristo

theme/nav.html

@@ -5,7 +5,7 @@
         <div class="navbar-header">
             {% if nav|length>1 or config.repo_url %}
             <!-- Expander button -->
-            <button type="button" class="navbar-toggle" data-toggle="collapse" data-target=".navbar-collapse">
+            <button type="button" class="navbar-toggle" data-toggle="collapse" data-target=".navbar-collapse" aria-expanded="false" aria-controls="navbar">
                 <span class="sr-only">Alternar navegação</span>
                 <span class="icon-bar"></span>
                 <span class="icon-bar"></span>