[plt-scheme] Bug report: Help desk, known-docs, etc.

I'm trying to add an HTML manual to the help desk.  Along the way, I've encountered several problems:

  * There's no way to add a 3rd-party manual to known-docs because it's a read-only module variable.

  * If the collects/help directory contains unknown manuals, the help-desk CGIs crash.

BTW, DrScheme is massively fun to hack on--the environment is really well designed, and it provides an unbelievably nice base from which to build custom languages.

Cheers,
Eric