readme: Update the K8s section (#2168)

Signed-off-by: Kimonas Sotirchos <kimwnasptd@arrikto.com>

README.md

@@ -80,9 +80,12 @@ The `example` directory contains an example kustomization for the single command
 
 ### Prerequisites
 
-- `Kubernetes` (tested with version `1.19`) with a default [StorageClass](https://kubernetes.io/docs/concepts/storage/storage-classes/)
+- `Kubernetes` (up to `1.21`) with a default [StorageClass](https://kubernetes.io/docs/concepts/storage/storage-classes/)
+    - :warning: Kubeflow 1.5.0 is not compatible with version 1.22 and onwards.
+        You can track the remaining work for K8s 1.22 support in
+        [kubeflow/kubeflow#6353](https://github.com/kubeflow/kubeflow/issues/6353)
 - `kustomize` (version `3.2.0`) ([download link](https://github.com/kubernetes-sigs/kustomize/releases/tag/v3.2.0))
-    - :warning: Kubeflow 1.4.0 is not compatible with the latest versions of of kustomize 4.x. This is due to changes in the order resources are sorted and printed. Please see [kubernetes-sigs/kustomize#3794](https://github.com/kubernetes-sigs/kustomize/issues/3794) and [kubeflow/manifests#1797](https://github.com/kubeflow/manifests/issues/1797). We know this is not ideal and are working with the upstream kustomize team to add support for the latest versions of kustomize as soon as we can.
+    - :warning: Kubeflow 1.5.0 is not compatible with the latest versions of of kustomize 4.x. This is due to changes in the order resources are sorted and printed. Please see [kubernetes-sigs/kustomize#3794](https://github.com/kubernetes-sigs/kustomize/issues/3794) and [kubeflow/manifests#1797](https://github.com/kubeflow/manifests/issues/1797). We know this is not ideal and are working with the upstream kustomize team to add support for the latest versions of kustomize as soon as we can.
 - `kubectl`
 
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