updated source link in docs

changed source link to matplotlib

also maybe turn on whatever it is that doesn't let people create new branches on the org repo?

Author: story645

docs/source/index.rst

@@ -10,7 +10,7 @@ This is prototype development for the next generation of data structures for
 Matplotlib.  This is the version "to throw away".  Everything in this
 repository should be considered experimental and used at you own risk.
 
-Source : https://github.com/tacaswell/data-prototype (for now)
+Source : https://github.com/matplotlib/data-prototype
 
 Examples
 --------