feat: add the guestbook app with kusionstack plugins.

Signed-off-by: Peefy <xpf6677@163.com>

plugins/kusionstack/README.md

@@ -0,0 +1,30 @@
+# KusionStack
+
+[KusionStack](https://kusionstack.io/) is a highly flexible programmable technology stack to enable unified application delivery and operation, which aims to help enterprises build an application-centric configuration management plane and DevOps ecosystem.
+
+Use the following steps to try the application:
+
+* Follow instructions from the [guide](https://kusionstack.io/docs/user_docs/guides/argocd/drift-detection-by-argocd) to make sure `kusion` binary is available in `argocd-repo-server` pod.
+* Register `kusion` plugin `argocd-cm` ConfigMap:
+
+```yaml
+apiVersion: v1
+data:
+  configManagementPlugins: |
+    - name: kusion
+      generate:
+        command: ["sh", "-c"]
+        args: ["kusion compile"]
+      lockRepo: true
+```
+
+* Create a guestbook application using `kusion` as a config management plugin name.
+
+```
+argocd app create guestbook-test \
+    --repo https://github.com/KusionStack/konfig.git \
+    --path appops/guestbook-frontend/prod \
+    --dest-namespace default \
+    --dest-server https://kubernetes.default.svc \
+    --config-management-plugin kusion
+```