Showing latest post on home page with Jekyll

index.html

---
layout: default
---

<div class="blog-index">  
  {% assign post = site.posts.first %}
  {% assign content = post.content %}
  {% include post_detail.html %}
</div>

post_detail.html

<h1 class="entry-title">
{% if page.title %}
    <a href="{{ root_url }}{{ page.url }}">{{ page.title }}</a>
{% endif %}
{% if post.title %}
    <a href="{{ root_url }}{{ post.url }}">{{ post.title }}</a>
{% endif %}
</h1>
<div class="entry-content">{{ content }}</div>