add examples

[phatpaul]

Some example usage of this plugin would be helpful for newbies like myself. Especially the extra options.
The test/index.js is the closest thing to an example I could find, and I had to hack around to figure out how to use this.

And then a quick example of what to do with the index.list files that are generated. I.e. converting them to html with metalsmith?

Thanks!