[racket] wffi (a "literate" web service "FFI" using a markdown file with parameterized HTTP messages)

> This is really neat! One thing I wonder is if there's a way to have
> tighter integration with the module system.  Say, a #lang-based
> Markdown-API language.

Thanks for the idea. That had flitted through my mind and it may even
be in the TODO file. It would be a great way for me to learn about
making a #lang.

I also noticed that the wiki for Sunday's HacketThon has an item about
the Google API Discovery service and JSON format. I didn't know about
that. There's a lot of overlap. Now I wonder if I should split this
into two parts:

1. A web service "FFI" that uses Google's JSON format (i.e. the
Hackathon project).
2. A markdown -> API JSON format tool, to make quick work of other web services.