Guide: no documentation for license

[Marko Käning]

>> I'd add a piece of text to the Guide to section 5.1 accordingly.
> 
> Consider matching:
> https://trac.macports.org/wiki/snc/licenses

Oh, I see, Jeremy, that's quite a piece of text already.

Hmmm, now I don't know anymore what makes sense to include in the rather incomplete MacPorts-Guide.
I'm willing to do some work here, but think it could be kept rather short then… (Just in line with the other short explanations in said section.)
Right?