jekyll/jekyll — pull request #3011 by fhemberger (2014-10-18 06:35:37+00:00)
Title: Docs: Clarify behavior of 'categories' in permalinks

I stumbled upon the behavior of `:categories` being resolved as category hierarchy in permalinks (and only found a note about this in a Stack Overflow answer, linking to [jekyllbootstrap.com](http://jekyllbootstrap.com/lessons/jekyll-introduction.html#toc_9)). So I added this to the docs as well.