Update Calico README for migration instructions
- For Calico, please send issues to [Calico repository](http://github.com/projectcalico/calico)
- For Tigera Operator, please send issues to [Operator repository](http://github.com/tigera/operator)
- We will update and maintain the [AWS docs](https://docs.aws.amazon.com/eks/latest/userguide/calico.html) for Calico installation after the deprecation
+- For users who want to migrate their Calico installation from Calico manifests based to operator based
+ - Making sure your Calico resources are in good working state
+ - Following [this Tigera instruction](https://projectcalico.docs.tigera.io/maintenance/operator-migration) to migrate
+ - Waiting till Calico resources migrated from `kube-system` namespace to `calico-system` namespace
+ - You should run network policy tests before you apply this migrated resources on prod environment
+- For users who want to upgrade their operator based Calico installation
+ - Till now, Tigera doesn't officially support migrating manifests installed operator to helm installed operator
+ - For users on manifests installed operator, you should follow [this instruction](https://projectcalico.docs.tigera.io/getting-started/kubernetes/quickstart) to upgrade your operator and managed Calico resources
+ - If you are upgrading Tigera operator, you should use `kubectl apply` instead of `kubectl create`
+ - For users on helm installed operator, you can follow [this instruction](https://projectcalico.docs.tigera.io/getting-started/kubernetes/helm) to use helm command to upgrade operator and its managed Calico to certain version
+- For users who want to stay on manifests installed Calico instead of Tigera operator
+ - Please be aware that this is a still supported method by Tigera but not preferred
+ - You can follow [this instruction](https://projectcalico.docs.tigera.io/getting-started/kubernetes/self-managed-onprem/onpremises) to upgrade to latest Calico resources
# Calico on AWS
