Write an article on cleaning up operator and operands

[alberttwong]

Similar to https://kubebyexample.com/learning-paths/operator-framework/operator-lifecycle-manager/cleaning-operators-and-operands

atwong@Albert-CelerData sroperatortest % kubectl get subscription -n starrocks
error: the server doesn't have a resource type "subscription"
atwong@Albert-CelerData sroperatortest % kubectl get clusterserviceversion -n starrocks
error: the server doesn't have a resource type "clusterserviceversion"
atwong@Albert-CelerData sroperatortest % kubectl delete starrocks starrocks
error: the server doesn't have a resource type "starrocks"
atwong@Albert-CelerData sroperatortest % kubectl delete -f starrocks-fe-and-be.yaml
starrockscluster.starrocks.com "starrockscluster-sample" deleted
atwong@Albert-CelerData sroperatortest % kubectl -n starrocks get pods
NAME                                      READY   STATUS    RESTARTS   AGE
kube-starrocks-operator-9bb77f7b9-bcqcm   1/1     Running   1          18h
atwong@Albert-CelerData sroperatortest % kubectl delete -f https://raw.githubusercontent.com/StarRocks/starrocks-kubernetes-operator/main/deploy/operator.yaml
namespace "starrocks" deleted
serviceaccount "starrocks" deleted
clusterrole.rbac.authorization.k8s.io "kube-starrocks-operator" deleted
clusterrolebinding.rbac.authorization.k8s.io "kube-starrocks-operator" deleted
role.rbac.authorization.k8s.io "cn-leader-election-role" deleted
rolebinding.rbac.authorization.k8s.io "cn-leader-election-rolebinding" deleted
deployment.apps "kube-starrocks-operator" deleted
atwong@Albert-CelerData sroperatortest % kubectl get all -n starrocks
No resources found in starrocks namespace.