I wrote a first translation of the design guide and added some little feedback. I won't register a github account. You can get this text here: http://dpaste.com/3H1C1JR.txt
In the Design Guide, the title is "p[h]rasenprüfer", while in the rest of the text, it's the more sensible ph[r]asenprüfer.
I'm sure this is an (understandable) typo - It would be neat if someone could fix that to avoid confusion.