Use package level marker to include KGO packages in CRDs reference

[czeslavo]

Problem Statement

Currently, to include types in the CRD reference, we rely on them to be annotated with a type-level marker +apireference:kgo:include. It can be problematic as we might miss adding the marker on a type while we expect all types defined in the KGO's repository to be included in the reference.

Proposed Solution

crd-ref-docs doesn't support propagating package-level markers to be accessed in templates. elastic/crd-ref-docs#95 aims to add it. Once it's merged and released, we will be able to switch to using a package-level marker and drop the type-level ones.

Additional information

Approach to doing so using the modified crd-ref-docs: chore/generate-docs-markdown-from-kconf...chore/generate-docs-package-level

Acceptance Criteria

• KGO's API definitions residing in https://github.com/Kong/gateway-operator/tree/6ee6a7c24f45c2b6831936f770fc6c89cdf904e5/api directory are included in the CRD reference based on the package-level +apireference:kgo:include-all-types marker