Document known Conditions (especially ResourcesHealthy) and how to consume them

[idoru]

Docs for Deliverable and Workload (e.g. https://cartographer.sh/docs/v0.4.0/reference/workload/) show that they have a Status containing Conditions. Similarly so for their Resources.Conditions.

The values of Conditions that may appear in this list (condition types, possible condition statuses and reasons) are not documented anywhere.

Whilst Condition itself a generic, core k8s concept, intrinsic cartographer behavior for conditions like Ready, or cartographer feature-specific behavior for conditions like Healthy are not, and we should enumerate the condition types that cartographer knowingly populates. This became painfully obvious when trying to understand how to meaningfully consume the outcome of a Template's healthRules.

In doing so, to allow them to be easily consumed, we should:

• offer clear explanation for the condition's meaning
• enumerate possible condition Status values, and what they mean in the context of this condition
• enumerate possible condition Reason values, and what they mean in the context of this condition, and where the next place to look

This may have some overlap with this existing doc: https://cartographer.sh/docs/v0.4.0/troubleshooting/

[squeedee]

Use generative docs to ensure all are captured in the crd ref.