Blog + Dynamic Podcast Episodes

@joellesteiniger I am merging this into master (but not deploying yet). This way, you can add the next episode tomorrow, and with that deploy you will take all the new changes live. When the blog posts are ready, we can update the navigation to actually point to them.

For now, I fixed the Tweet buttons, and the background color bug. Let me know if anything else needs fixing. You can delete your local `feature/detail_pages` branch and make all future changes on `master` (but pull down first).