What's the plan to keep this up to date, though? Wouldn't having this in a wiki or something make more sense than a PDF?
The LaTeX sources for the document are in github. Because LaTeX is essentially 'plain-text' it is simple to work with and easy to version, etc. And depending on your toolchain you could generate output in pretty much any format, but I personally like PDF - easy to read, easy to search, easy to share, etc., etc.
Anyways, a new version of the document with keyboard cable instructions is attached - note I haven't actually made one of these, so perhaps someone could double check the instructions and let me know if anything needs correcting or clarification.
Enjoy,
D.
[Latest version of the guide attached to first post]