How do I add a sidebar to the layout?

[marcamillion]

Right now, the entire page just has datestamp in left column and post in the middle.

In my _config.yml, I have tried both this:

default_asides: [asides/about.html]

and this:

default_asides: [custom/asides/about.html]

I have that file in my source/_includes/custom/asides/

But it doesn't show that aside at all.

This is the content of that about.html:

<section>
  <h1>About Me</h1>
  <p>A little something about me.</p>
</section>

Thoughts?