Create a feed of package updates

The [`feedstocks` repo]( https://github.com/conda-forge/feedstocks ) (linked for those that don't know), is live updated for any change in conda-forge. GitHub also provides the ability to have an Atom feed. Here is the feed regarding [individual feedstock updates]( https://github.com/conda-forge/feedstocks/commits/master.atom ) just the commits on `master`. Would be great to stick that feed link on the website possibly under a feed icon ([this]( https://commons.wikimedia.org/wiki/File:Rss-feed.svg ) is Public Domain and could work). 😄