organize and update deployment docs

[qrkourier]

aims include:

1. position deployment docs more prominently
2. focus deployment docs on what's required by creating a landing page for controller, router, and console
3. update deployment docs to assume clustered mode by default
4. highlight overriding defaults, customizing config, etc. so there's no confusion about the purpose of the included configuration utility, which only creates PKI, config.yml, and initializes database if those are not provided by the user