Consolidate documentation

[afred]

Because

We have deploy_instructions and README.md and the deploy script's USAGE that displays when you run it. Would be great if this was all just in the README.md, keeping the in-line docs in deploy.

Background

Using the Docker container (with the docker script) is very convenient and can be done without having to set up a local Ruby environment. However inside the Docker container is a Capistrano deployment, which should still be able to be used if you want to set up your local Ruby environment (e.g. with rvm), or if you are modifying the deployment code and/or the container and need to shell into it. Point being, the docs about running the cap commands are still relevant, so let's keep them.

Done when

• README.md is reviewed
• Deploy instructions are copied into README.md.
• "Happy path" deployment is clear using code block for quick copy+paste