Added dutch translation of readme.md for Minecraft

Hi,

I'm an employee of JPoint and we will be organising a devoxx4kids day coming September 20th at the university of Amsterdam. I've translated the readme for Minecraft to dutch and like to share it with you for future use. Probably more pull request will be requested since more colleagues of JPoint are preparing their workshops. Maybe I could become a contributor?

Best regards, Gijs