Little omission on instructions to compile Windows VM

Hi:

I compiled my own vm and found a little omission on the page
http://www.squeakvm.org/win32/compiling.html, in the Customization
section.

As is needed a custom MyCustomVM.rc, also is needed a
MyCustomVM.def.in to successful compile the VM.

Hope this help others.

Cheers.

--
Germán S. Arduino
http://www.arsol.biz
http://www.arsol.net