created Readme.txt to for reproducible_randomness exercise

I'd like to contribute to this open book. I added a directory and included a Readme.txt to explain what I'd be up to. It's unclear how it overlaps with "proba-ecological-networks"? Any ideas?
The material is pretty much set inn my head and I'd like to go forward to commit. The question for me is how to convey the contents: just source code or ipython notebooks or markdown only or ....

As always, please provide feedback!

Best,