Simplify config creation

Convert config creation from a playbook to an action_plugin. This
reduces the complexity and confusion while retaining the same augment
structure and flexibility.

This allows us to remove the 0-byte files as requirements. They will
still be used if they are present (this means we require additional
documentation around them).

DocImpact
Closes-Bug: #1528430
Change-Id: I2c789f6be9f195c7771ca093a6d59499564b4740