doc: update reference with name of page
Update docs/book/src/cronjob-tutorial/testdata/project/api/v1/cronjob_webhook.go
@@ -161,7 +161,8 @@ func (r *CronJob) validateCronJob() error {
/*
Some fields are declaratively validated by OpenAPI schema.
You can find kubebuilder validation markers (prefixed
-with `// +kubebuilder:validation`) in the [API](api-design.md)
+with `// +kubebuilder:validation`) in the
+[Designing an API](api-design.md) section.
You can find all of the kubebuilder supported markers for
declaring validation by running `controller-gen crd -w`,
or [here](/reference/markers/crd-validation.md).
