Add note for cni versions compatibility (openshift-service-mesh#525)

* Add note for cni versions compatibility

Signed-off-by: bmangoen <[email protected]>

* Fix typo

Signed-off-by: bmangoen <[email protected]>

---------

Signed-off-by: bmangoen <[email protected]>

Author: bmangoen

docs/README.md

@@ -114,6 +114,9 @@ spec:
       - kube-system
 ```
 
+> [!NOTE]
+> The CNI plugin at version `1.x` is compatible with `Istio` at version `1.x-1`, `1.x` and `1.x+1`. 
+
 ## API Reference documentation
 The Sail Operator API reference documentation can be found [here](https://github.com/istio-ecosystem/sail-operator/tree/main/docs/api-reference/sailoperator.io.md).