Update README.md

README.md

@@ -6,6 +6,18 @@ A tool to check product keys for Windows and Office
 
 A pkeyconfig file (resembling `pkeyconfig-xyz.xrm-ms`) is required to use this. The pkeyconfig for Windows 11 22H2 is included by default. Other pkeyconfig files (sourced from [SimplePidX](https://forums.mydigitallife.net/threads/simplepidx-simple-yet-powerful-product-key-checker.80300/)) can be downloaded [here](https://files.catbox.moe/9tkls4.7z).
 
+## Usage
+
+Individual product keys can be checked like so: `python keycheck.py pkey <Product Key>`
+
+For a given product key, the output will either show it as online-valid or will display error information from the server.
+
+A text file of product keys, one key per line, can be checked like so: `python keycheck.py batch <Keys File>`
+
+For batch activation, the list of valid keys will be printed at the end of the check. A full log containing error information will be saved to an output file (default `log.txt`)
+
+For more information, run `python keycheck.py --help`.
+
 ## Credits
 
 Many thanks to [asdcorp](https://github.com/asdcorp) for assistance in development and testing.