doc: patterns for using Nulecule Spec

[goern]

As an ISV, I want to package my application according to the Nulecule Spec, so that it can deploy a 'organization wide' or a 'per team' application.

We need to document these two categories of application packaging pattern. And propose a way how to do it using Nulecule/AtomicApp.

[aweiteka]

Consider landing here: https://github.com/projectatomic/container-best-practices