README: add a note about 64-bit Wine needing 32-bit Wine to work

[Dmitry Timoshkov]

Austin English <austinenglish at gmail.com> wrote:

> +  http://wiki.winehq.org/Wine64 for details. Note that a 64-bit Wine
> +  build will not work without also building 32-bit Wine.

This statement is not true in general.

Actually 64-bit Wine build works just fine without any 32-bit part. That's
just a useless configuration, but it's a minor detail.

-- 
Dmitry.