update readme

Signed-off-by: Zhonghu Xu <xuzhonghu@huawei.com>

README.md

@@ -74,11 +74,21 @@ Note: * Planning
   kmesh-system   kmesh-l5z2j                                 1/1     Running   0          117m
   ```
 
+- Enable Kmesh For a Namespace
+
+  Add `istio.io/dataplane-mode=Kmesh` label to the namespace which you want to take over by kmesh, now all workloads' ingress/egress traffic will be managed by kmesh.
+
+  ***Note: pod started before will not be influenced***
+
+  ```bash
+	kubectl label namespace {namespace} istio.io/dataplane-mode=Kmesh
+  ```
+
 - Remote L7 Trafic Management
 
-Kmesh now support advanced L7 processing via waypoint, with which it can achieve equivalent traffic management capabilities with Istio. But kmesh makes use of ebpf to do traffic interception and redirection, it provides more simplicity and higher performance.
+Kmesh now support advanced L7 processing via waypoint, with which it can achieve equivalent traffic management capabilities with Istio. But kmesh makes use of eBPF to do traffic interception and redirection in local node, it provides more simplicity and higher performance.
 
-  - Deploy a waypoint for serviceaccoount `default`
+  - Deploy a waypoint for service account `default`
 
     ```bash
     [root@ ~]# istioctl x waypoint apply --service-account default