Printing the book problem: Header overwrites content

[anotherchrisatwork]

Hello,

Thanks for doing this book! It's fantastic.

However, I printed a copy and found that every page had a banner at the top with "TOC v" (where the "v" represents a down-arrow). This wouldn't be a big deal, but it covers up lines of content on several pages.

It'd be great if the code could be modified to hide the "

" element on printing.

I'll do a fix and pull request, if you like.

Thanks again!