(#2469) - blog post about PouchDB + LevelUP

Looking for feedback on this from @calvinmetcalf and maybe @rvagg / @juliangruber if you aren't busy. I don't want to misrepresent LevelDB or LevelUP, and I'm definitely not an expert on either, but I think the Pouch+LevelUP integration is exciting enough to warrant a blog post.
also hyperdex might be worth noting, IMO they have the most impressive fork of leveldb (available in levelup form as level-hyper which uses leveldown-hyper)