Add info on running in non-Vagrant envs to README

Hi,

When I first looked at the project, I wished that it told me how to run it in real environments. So I did that. Fixes some little Markdown issues too like numbered list syntax.

I also wish that the README told me about some things like the concurrency model. I'm still testing it myself and also getting acquainted with Kafka's Java APIs that are used, as well as Dropwizard/Jetty, in order to understand this, but if any maintainers can add that info it'd be great.