Document how to use API operator to manage deployments of the same configuration in multiple environments.

Pre-requisites: 3scale, OCP, OAS.
OAS can be pushed to 3scale with Toolbox (pending).
OAS can be generated using Apicurio.

The CRD has 2 parts: OAS and API object (3scale config).
The CRD is a YAML file that can be edited directly or in the OCP UI.
Changes in the CRD will get reflected in 3scale.
Changes in 3scale won't get reflected in CRD spec.

In 2.5. this will be released Technology Preview.