[plt-dev] Documentation Suggestion for mred-text

Per a discussion with Eli today on #scheme, I've modified a copy of
http://svn.plt-scheme.org/plt/trunk/collects/scribblings/guide/running.scrbl
to include instructions for running MrEd applications in text terminal
or editor. Specifically, I put the following just before
`start-module-mode':

@subsubsection[#:tag "start-mred-text"]{Using @exec{mred} in a Text Interface}

Programmers who wish to use libraries that require @exec{mred} (such as
@schememodname{scheme/gui}) interactively in a text-based interface like
a terminal window or text editor should use the @exec{mred-text}
executable. Using @exec{mred-text} lets the programmer interactively
debug graphical applications without using DrScheme or the MrEd GUI
@tech{REPL}. Running @exec{mred} with @Flag{z} gives similar behavior
but causes some problems, especially on Windows.


---Karl