[update] ambiguous readme doc.

README.md

@@ -79,7 +79,7 @@ Open the AT device software package. This version only supports **Enable one AT
 
 - **Enable at device init by thread**: Configure whether to enable the device network initialization to be completed by creating a thread;
 
-- **AT socket device modules**: AT device selection, currently supports RW007, ESP8266, M26/MC20, EC20, SIM800C, SIM76XX, A9/A9G, BC26, air720, ME3616, M6315, BC28, EC200X, M5311 and other devices;
+- **AT socket device modules**: AT device selection, currently only supports RW007、ESP8266、M26/MC20、EC20、SIM800C、SIM76XX. More device support should choose V2.X.X branch.
 
 - **Version**: download the software package version;
 
@@ -207,4 +207,3 @@ Among them, the configuration options related to the AT device software package:
 * Maintenance: RT-Thread development team and community developers
 * Homepage: https://github.com/RT-Thread-packages/at_device
 
-

README_ZH.md

@@ -78,7 +78,7 @@ AT device 软件包目前已经发布多个版本，各个版本之间选项配
                   Version (V1.6.0)  --->
 
 - **Enable at device init by thread**: 配置开启设备网络初始化是否通过创建线程完成；
-- **AT socket device modules**: AT 设备选择，目前支持 RW007、ESP8266、M26/MC20、EC20、SIM800C、SIM76XX、A9/A9G、BC26 、air720、ME3616、M6315、BC28、EC200X、M5311等设备；
+- **AT socket device modules**: AT 设备选择，目前仅支持 RW007、ESP8266、M26/MC20、EC20、SIM800C、SIM76XX；更多的设备支持请选择 V2.X.X 分支。
 - **Version**: 下载软件包版本；
 
 **V2.X.X (latest) 版本配置选项介绍**