Add like to Python 3 for scientists

Author: takluyver

_sections/50-why.md

@@ -15,4 +15,5 @@ code to use Python 3:
 - [How to add Python 3 support to your code](https://docs.python.org/3/howto/pyporting.html)
 - [Stop supporting Python 2.6 for free](http://www.curiousefficiency.org/posts/2015/04/stop-supporting-python26.html) (Nick Coghlan)
 - [Why Python 4.0 won't be like Python 3.0](http://www.curiousefficiency.org/posts/2014/08/python-4000.html) (Nick Coghlan)
+- [Python 3 for scientists](http://python-3-for-scientists.readthedocs.io/en/latest/)
 - [scikit-bio py3-only RFC](https://github.com/biocore/scikit-bio-rfcs/blob/master/accepted/002-py3-only.md)