add mark

Author: TOwInOK

README.md

@@ -31,6 +31,7 @@ It provides:
 Marks:
 - Ready to use: ✅
 - Unstable (do not use it in any ways, only at your own risk): ⚠️
+- without marks: not tested, only at your own risk
 ---
 [list of commands](https://apidoc.whatsminer.com/):
 - [x] [get.device.custom_data](https://apidoc.whatsminer.com/#api-Device-device_get_custom_data)