Render Engine for basic pages
Add Liquid
Add Liquid to the rendering
Don't allow protected instance variables in public
Add forgery protection
Add the Forum model
Add to_liquid to Forum to use for rendering

Example forum/index template:

<h1>This is a page!</h1>
<p>Sup, hi theree!</p>
{{ 'now' | date: "%Y %h" }}

{% for forum in forums %}
<p>{{forum.name}}</p>
{% endfor %}