doc: upgrade from v1.1 to v1.2

Signed-off-by: changzhen <changzhen5@huawei.com>

docs/upgrading/README.md

@@ -13,6 +13,7 @@
     - [v0.9 to v0.10](#v09-to-v010)
     - [v0.10 to v1.0](#v010-to-v10)
     - [v1.0 to v1.1](#v10-to-v11)
+    - [v1.1 to v1.2](#v11-to-v12)
 
 <!-- END doctoc generated TOC please keep comment here to allow auto update -->
 
@@ -79,3 +80,4 @@ v1.1.x to v1.2.x and the available patch versions are v1.2.0, v1.2.1 and v1.2.2,
 ### [v0.9 to v0.10](./v0.9-v0.10.md)
 ### [v0.10 to v1.0](./v0.10-v1.0.md)
 ### [v1.0 to v1.1](./v1.0-v1.1.md)
+### [v1.1 to v1.2](./v1.1-v1.2.md)

docs/upgrading/v1.1-v1.2.md

@@ -0,0 +1,53 @@
+# v1.1 to v1.2
+
+Follow the [Regular Upgrading Process](./README.md).
+
+## Upgrading Notable Changes
+
+### karmada-controller-manager
+
+The `hpa` controller has been disabled by default now, if you are using this controller, please enable it as per [Configure Karmada controllers](https://github.com/karmada-io/karmada/blob/master/docs/userguide/configure-controllers.md#configure-karmada-controllers).
+
+### karmada-aggregated-apiserver
+
+The deprecated flags `--karmada-config` and `--master` in v1.1 have been removed from the codebase.
+Please remember to remove the flags `--karmada-config` and `--master` in the `karmada-aggregated-apiserver` deployment yaml.
+
+### karmadactl
+
+We enable `karmadactl promote` command to support AA. For details info, please refer to [1795](https://github.com/karmada-io/karmada/pull/1795). 
+
+In order to use AA by default, need to deploy some RBAC by following manifests.
+
+<details>
+<summary>unfold me to see the yaml</summary>
+
+```yaml
+apiVersion: rbac.authorization.k8s.io/v1
+kind: ClusterRole
+metadata:
+  name: cluster-proxy-admin
+rules:
+- apiGroups:
+  - 'cluster.karmada.io'
+  resources:
+  - clusters/proxy
+  verbs:
+  - '*'
+---
+apiVersion: rbac.authorization.k8s.io/v1
+kind: ClusterRoleBinding
+metadata:
+  name: cluster-proxy-admin
+roleRef:
+  apiGroup: rbac.authorization.k8s.io
+  kind: ClusterRole
+  name: cluster-proxy-admin
+subjects:
+  - kind: User
+    name: "system:admin"
+```
+
+</details>
+
+Please refer to [v1.2.0 Release Notes](https://github.com/karmada-io/karmada/releases/tag/v1.2.0) for more details.