[x] add guid, filename, file size, audio length to all front matter
[x] create a post for every podcast episode (parse the rss feed?)
[ ] add description to site config
[ ] add subtitle to site config
[ ] generate urls from title, not from category (prettier urls)
[ ] prettier styles for audio player
[ ] fix encoded html tags sneaking in to podcast feed
[ ] validate feed (http://castfeedvalidator.com/?url=http://podcastersroundtable.com/feed/podcast/)
[ ] fiter podcast rss feed so only actual podcast episodes go in it, not blog posts
[ ] generate a comma-separated list of itunes keywords from post tags
[ ] links to our podcast on itunes . . . somehow?
[ ] twitter cards (http://matthewlincoln.net/2015/04/01/twitter-cards-in-jekyll.html)
[ ] lastBuildDate on rss feed - what does that do?
[x] grab excerpt from post to put in podcast rss feed
[ ] look at making the excerpt make more sense?
what does the image tag in the rss feed do?