docs/_includes/post_details.html

{% unless post %}
  {% assign post = page %}
{% endunless %}

{% assign post_author = post.author %}
{% assign post_gravatar = 'http://www.fillmurray.com/82/82' %}
{% assign modified_date = '' %}

{% for author in site.data.authors %}
  {% if author.name == post.author %}
    {% if author.twitter %}
      {% capture post_author %}<a href="https://twitter.com/{{author.twitter}}">{{ post.author }}</a>{% endcapture %}
    {% endif %}
    {% if author.gravatar %}
      {% capture post_gravatar %}https://gravatar.com/avatar/{{ author.gravatar }}{% endcapture %}
    {% endif %}
  {% endif %}
{% endfor %}

{% if post.modified_date %}
  {% capture modified_date %}<strong>Updated:</strong> {{ post.modified_date | date_to_long_string }}<br>{% endcapture %}
{% endif %}

<div class="post">
  <div class="media">
    <a class="pull-left" href="#">
    <img class="media-object img-circle img-responsive" src='{{ post_gravatar }}' alt='{{ post.author }}'>
    </a>
    <div class="media-body">
    <p>
      <strong>By:</strong> {{ post_author }}<br>
      <strong>Published:</strong> {{ post.date | date_to_long_string }}<br>
      {% if page.url == "/blog/index.html" or page.url contains "/blog/page" or page.url == "/index.html" %}
        {{ post.excerpt | strip_html | truncatewords: 30, '' }}
        <a href='{{ site.baseurl }}{{ post.url }}'>[...]</a>
      {% endif %}
    </p>
    </div>
  </div>
</div>