[MLton] style guide

[Stephen Weeks]

> > Since there is renewed interest in the style guide,
...
> I don't think it really belongs in the User Guide.  I imagine that
> the majority of users aren't going to be hacking the compiler
> sources, so it doesn't really apply.  We could probably migrate the
> bit that discusses sig/struct conventions into an intro the the
> MLton structure extension.

The style guide is intended to be relevant to far more than compiler
hackers.  It is intended to be applicable to general SML development.
I agree that some of it doesn't apply to the MLton structure.  I don't
think it's a good idea to break up the style guide.

Another possiblity would be to put the style guide as a standalone
document on the web site.  It could be added as an additional item in
the navigation bar, or, we could create a new separate navigation
item, "documentation", and move the user guide and style guide there
(perhaps even the history or papers too?).  My gut feeling is that
we're approaching the limit of the current navigation bar, but that
one more item may be ok.