Bug Fix in docs/theme/template/

There is a bug in http://octopress.org/docs/theme/template/, at the second code block in **Changing the sidebar**, where `render_partial` returns error:

>File /Users/parkermoore/code/octodocs/.themes/classic/source/_includes/custom/asides/about.html could not be found`

You can accept my patch or fix the path above at your discretion.

Regards,
\- Colin