documentation for Control.Monad.State

[Simon Marlow]

> Here's a patch which adds some Haddock documentation to the
> Control.Monad.State module.  I collected examples together that I had
> found useful when trying to understand this module, and haddock-ized
> some of the comments that were already in the code.  I also got
> permission from the original authors to include these examples.
>=20
> The resulting haddock output can be seen here:
> http://www.syntaxpolice.org/~ijones/tmp/Control.Monad.State.html
>=20
> Any comments before I commit this patch are welcome.

I think moving the examples into a separate "Examples" section on that
page would be better.  As it is, the examples cause too much of a gap
between the data types and their constructors.

Cheers,
	Simon=20