Print-friendly css

[matthewmueller]

Tried to add this as pull request, but couldn't get all the rake dependencies to build the document.

Basically just add another css file for print media = "print" or I think you can do:

@media print {
    ...
}

... and just hide the sidebar. Then us old timers can have our paper copy :-)

[sharper-than-blade]

hi, I think the css for this document is really awsome, and I would like to reuse it to prettify my documentations. How can I do that?