Appendix: Use of Mako to aid book writing

Remark. Documents that contain raw Mako code in verbatim code blocks cannot also be processed by Mako, and this is the case with the mako chapter. Since we need Mako for processing the rest of this book document, we are forced to compile the mako chapter as a stand-alone document (with the --no_mako option) and let this appendix be just a link to the this stand-alone document.