Proposal: Definition of Krateo Module manifest & controller behaviour

[braghettos]

Scope of this issue is to define the specification for the Krateo Module manifest and what we expect from its controller.

[braghettos]

Based on #4, there is no reason to implement an abstraction upon Crossplane claims.

[braghettos]

My proposal is to call every GitHub repository which contains a composition 'krateo-module-*'. The apiGroup of the Composite Resource Definition will remain deployment.krateo.io. To list all Krateo Module resources we will use the following command: kubectl get configuration.