!1230 【子系统】：更新readme

Merge pull request !1230 from yaoyueyu/master

zh-cn/device-dev/subsystems/Readme-CN.md

@@ -40,6 +40,13 @@
     - [唤醒词识别SDK的开发示例](subsys-aiframework-demo-sdk.md)
     - [唤醒词识别插件的开发示例](subsys-aiframework-demo-plugin.md)
     - [唤醒词识别配置文件的开发示例](subsys-aiframework-demo-conf.md)
+- [数据管理](subsys-data.md)
+  - [关系型数据库](subsys-data-relational-database.md)
+    - [关系型数据库概述](subsys-data-relational-database-overview.md)
+    - [关系型数据库开发指导](subsys-data-relational-database-guide.md)
+  - [轻量级数据存储](subsys-data-storage.md)
+    - [轻量级数据存储概述](subsys-data-storage-overview.md)
+    - [轻量级数据存储开发指导](subsys-data-storage-guide.md)
 - [Sensor服务](subsys-sensor.md)
   - [Sensor服务子系概述](subsys-sensor-overview.md)
   - [Sensor服务子系使用指导](subsys-sensor-guide.md)