<header>

<div>
  <a rel="author" href="{{ "/" | relative_url }}"><h1>{{ site.title | escape }}</h1></a>
</div> 
<nav>
  <ul>
    {%- assign links = site.data.navigation -%}
    {%- for link in links -%}
        <a href="{{ link.url | relative_url }}">{{ link.title | escape }}</a>
    {%- endfor -%}
  </ul>
</nav>

</header>