[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.

Fixed in the CVS source and for the upcoming v202.  If you want a fix
for v201, let me know -- it's a change to one small subexpression.

You won't need to add to known-docs -- any subdirectory of
plt/collects/doc with an `index.htm' file will work.  You'll need to
generate an hdindex file for Help Desk to search your docs.

-- Paul