<nav class=“header-nav”>

<div>
  {% if site.github %}
  <a href="https://github.com/{{ site.github }}">github</a>
  {% endif  %}
  {% if site.twitter %}
    <a href="https://twitter.com/{{ site.twitter }}">twitter</a>
  {% endif  %}
  {% if site.email %}
    <a href="mailto:{{ site.email }}">email me</a>
  {% endif  %}
</div>
<div>
  <a href="{{ "/" |  relative_url }}">home</a>
  <a href="{{ "/about" | relative_url }}">about</a>
</div>

</nav>