[plt-scheme] More document (newbie)

> I wanted to thank everyone in PLT for the immense effort that has and is
> being poured into documentation.

even though i've had some issues with PLT docs, mostly as a result of
my local minima as a specific type of user, i have to say the fact
that there are docs at all and of such detail is a zillion times
better than cough cough certain other Scheme implementations i have
tried to look at and experiment with and learn. (and by "certain" i
seem to mean "everything not PLT" :-)

so another thanks from a struggling newbie-ish.