[racket] starting a small guide on programmatic scribble usage

The beginnings of a draft:

    http://hashcollision.org/tmp/using-scribble-programmatically/using-scribble-programmatically.html

Basically, it's some quick-and-dirty notes I'm keeping to myself as I
get prepared to correct the kludgy build script I used to generate
Scribble documents during the summer.  I'd appreciate any suggestions
and corrections.


Thanks!