added vertical asides (top/bottom)

I've found your library and I like it a lot, but I also needed an aside (so to speak) but on the bottom. I figured I'd add one on the top as well just in case someone might need that as well. Here's the plunk I've updated the readme with: http://plnkr.co/edit/MoHT8o31AP3xDwF8a9oD?p=preview