FW0.6.0 features:
1. Support NanoVNA-APP (as the original author has not checked the PR yet, only the SYSJOINT branch version is currently available：https://github.com/sysjoint-tek/NanoVNA-App/releases);
2. New feature of saving trace data to .csv file. Menu path: [STORAGE] -> [SAVE CSV];
3. New feature of SAVE DELAY (Data will be saved after a certain delay, which facilitates the measurement of DUTs that are susceptible to the surrounding environment). Menu path: [STORAGE] -> [SAVE DELAY];
4. The buzzer can be turned off: creat a file named "beep_off.txt" at the root directory of the device (the virtual U-disk) and write the number 1 into the file;
5. Add a new serial command of "vbat" for NanoVNA-APP;
6. Optimized battery icon and voltage display;
7. Supports TCXO frequency correction (only for hardware version D). Menu path: [CAL] -> [TCXO];


v0.6.0固件特性：
1、支持NanoVNA-APP上位机（由于NanoVNA-APP原作者还未接受PR，目前仅可使用SYSJOINT分支版本：https://github.com/sysjoint-tek/NanoVNA-App/releases）。
2、新增保存迹线数据至CSV文件，菜单路径：【储存功能】->【保存CSV】。
3、新增延时保存功能（可在延迟一定时间后再保存数据，以便于测量那些容易受周围环境影响的DUT），菜单路径：【存储功能】->【延时设置】。
4、蜂鸣器关闭功能：在设备的根目录（虚拟U盘）创建一个beep_off.txt，并写入1。
5、增加vbat命令，适配NanoVNA-APP。
6、电池图标及电压显示优化。
7、支持晶振频率修正（仅支持D版本硬件），菜单路径【校准】->【晶振校准】。