<nav class=“navbar navbar-expand-lg navbar-light bg-light mb-4”>

<div class="container">
  <a href="{{ "/" | relative_url }}" class="navbar-brand">{{ site.title | escape }}</a>
  <button type="button" class="navbar-toggler" data-toggle="collapse" data-target="#app-navbar" aria-controls="app-navbar" aria-expanded="false" aria-label="Toggle navigation">
    <span class="navbar-toggler-icon"></span>
  </button>
  <div class="collapse navbar-collapse" id="app-navbar">
    <ul class="navbar-nav ml-auto">
      {%- include topnav.html -%}
    </ul>
  </div>
</div>

</nav>