Document Tinkerbell's Kubernetes back-end

[chrisdoherty4]

Customers are asking for additional documentation on debugging the Tinkerbell stack. This typically includes understanding the Kubernetes back-end of Tinkerbell and the various types available in the cluster for inspection. This documentation should be available upstream in the Tinkerbell project and we should be able to reference it in EKS-A documentation.

This task is to contribute to the Tinkerbell project's documentation and subsequently reference the new docs from EKS-A.

Related issues

• Write Kubernetes back-end documentation tinkerbell/tinkerbell-docs#146
• Document the Kubernetes back-end deployment tinkerbell/playground#147