[Cryptech Core] minor updates to the donators doc

[Leif Johansson]

https://wp.cryptech.is/wp-uploads/2014/04/Donating-to-the-Cryptech-Project1.pdf

Cleaned up some detailed comments from our CFO, notably added a note
about not endorsing services or products in recognition This avoids
potential legal problems with something called Tekal protection and is
probably a good idea anyway just to keep expectations under control.

	Cheers Leif