docs: add CRD v2 reference document

Author: keynslug

Makefile

@@ -97,6 +97,17 @@ build: manifests generate fmt vet ## Build manager binary.
 run: manifests generate fmt vet ## Run a controller from your host.
 	go run ./cmd/main.go
 
+.PHONY: doc
+doc: crd-ref-docs manifests doc-crd-v2 ## Generate documentation for the CRDs.
+
+.PHONY: doc-crd-v2
+doc-crd-v2: ## Generate documentation for the `apps.emqx.io/v2` CRD.
+	$(CRD_REF_DOCS) \
+		--source-path=api/v2 \
+		--config=crd-ref-docs-config.yaml \
+		--output-path=docs/en_US/reference/v2-reference.md \
+		--renderer=markdown
+
 # If you wish to build the manager image targeting other platforms you can use the --platform flag.
 # (i.e. docker build --platform linux/arm64). However, you must enable docker buildKit for it.
 # More info: https://docs.docker.com/develop/develop-images/build_enhancements/
@@ -178,12 +189,14 @@ KUSTOMIZE ?= $(LOCALBIN)/kustomize
 CONTROLLER_GEN ?= $(LOCALBIN)/controller-gen
 ENVTEST ?= $(LOCALBIN)/setup-envtest
 GOLANGCI_LINT = $(LOCALBIN)/golangci-lint
+CRD_REF_DOCS ?= $(LOCALBIN)/crd-ref-docs
 
 ## Tool Versions
 KUSTOMIZE_VERSION ?= v5.5.0
 CONTROLLER_TOOLS_VERSION ?= v0.18.0
 ENVTEST_VERSION ?= release-0.19
 GOLANGCI_LINT_VERSION ?= v1.64.8
+CRD_REF_DOCS_VERSION ?= latest
 
 .PHONY: kustomize
 kustomize: $(KUSTOMIZE) ## Download kustomize locally if necessary.
@@ -205,6 +218,11 @@ golangci-lint: $(GOLANGCI_LINT) ## Download golangci-lint locally if necessary.
 $(GOLANGCI_LINT): $(LOCALBIN)
 	$(call go-install-tool,$(GOLANGCI_LINT),github.com/golangci/golangci-lint/cmd/golangci-lint,$(GOLANGCI_LINT_VERSION))
 
+.PHONY: crd-ref-docs
+crd-ref-docs: $(CRD_REF_DOCS) ## Download crd-ref-docs locally if necessary.
+$(CRD_REF_DOCS): $(LOCALBIN)
+	$(call go-install-tool,$(CRD_REF_DOCS),github.com/elastic/crd-ref-docs,$(CRD_REF_DOCS_VERSION))
+
 # go-install-tool will 'go install' any package with custom target and name of binary, if it doesn't exist
 # $1 - target path with name of binary
 # $2 - package url which can be installed

crd-ref-docs-config.yaml

@@ -0,0 +1,8 @@
+processor:
+  ignoreFields:
+    - "TypeMeta$"
+  ignoreTypes:
+    - "EMQXList$"
+
+render:
+  kubernetesVersion: 1.32

docs/en_US/reference/overview.md

@@ -0,0 +1,4 @@
+# API Reference
+
++ [apps.emqx.io/v2](./v2-reference.md)
++ [apps.emqx.io/v2beta1](./v2beta1-reference.md) (partially deprecated)