add blurb about mounting secrets to the containers

crd-docs/crd/kiali.io_kialis.yaml

@@ -218,7 +218,7 @@ spec:
                     items:
                       type: string
                   additional_pod_containers_yaml:
-                    description: "Additional containers to add to the list of pod containers. Use this to add a sidecar(s) to the Kiali pod. Use with care since sidecars may cause the Kiali container itself to operate incorrectly. It is up to the user who added the additional containers to ensure it works properly inside the Kiali pod; Kiali makes no guarantee additional containers will work."
+                    description: "Additional containers to add to the list of pod containers. Use this to add sidecar(s) to the Kiali pod. Use with care since sidecars may cause the Kiali container itself to operate incorrectly. It is up to the user who added the additional containers to ensure it works properly inside the Kiali pod; Kiali makes no guarantee additional containers will work. You can utilize container environment variables to pass data to the containers via mounted custom secrets (see spec.deployment.custom_secrets)."
                     type: object
                     x-kubernetes-preserve-unknown-fields: true
                   additional_service_yaml: