Documentation Improvement

I'm just getting started using CollectionFS, but I found the readme a bit disorganized and confusing. I have experience writing software documentation, so I figured I'd lend a hand, if only because writing docs often helps me understand better. Here's an extensive rewrite of the readme with better organization, rewording, and some clarified and simplified examples. There isn't much new content, but I rewrote a bunch of it, so you should read through for accuracy before pulling. Oh, I added an example of file removal, too. I'm not sure if it's correct since I haven't tried it in an app yet.

The filehandler example section could probably be cleaned up and explained more, too, but I don't have any more time at the moment. Not sure if I'll have time, but I might be able to do some of the simple code enhancements at some point. I don't have much knowledge of buffers, streams, filesystems, and such, but I could handle built-in handlebar helpers, built-in filehandlers, built-in templates, etc. I'm not sure what your exact roadmap is; looks like you're planning an overhaul soon.