update plugins doc (#1305)

plugins/wasm-go/extensions/ai-agent/README.md

@@ -9,6 +9,10 @@ description: AI Agent插件配置参考
 agent流程图如下：
 ![ai-agent](https://github.com/user-attachments/assets/b0761a0c-1afa-496c-a98e-bb9f38b340f8)
 
+## 运行属性
+
+插件执行阶段：`默认阶段`
+插件执行优先级：`20`
 
 ## 配置字段
 
@@ -347,4 +351,4 @@ curl 'http://<这里换成网关公网IP>/api/openai/v1/chat/completions' \
 
 ```json
 {"id":"65dcf12c-61ff-9e68-bffa-44fc9e6070d5","choices":[{"index":0,"message":{"role":"assistant","content":" “九头蛇万岁!”的德语翻译为“Hoch lebe Hydra!”。"},"finish_reason":"stop"}],"created":1724043865,"model":"qwen-max-0403","object":"chat.completion","usage":{"prompt_tokens":908,"completion_tokens":52,"total_tokens":960}}
-```
+```