new: save/load user data

README.md

@@ -50,6 +50,11 @@ wget https://github.com/mirrors2/opencatd-open/raw/main/docker/docker-compose.ym
 >重置 root 的 token 
   - `docker exec opencatd-open opencatd reset_root` 
 
+>导出 user info -> user.json (docker file path: /app/db/user.json)
+  - `docker exec opencatd-open opencatd save`   
+
+>导入 user.json -> db 
+  - `docker exec opencatd-open opencatd load` 
 
 ## Q&A
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