docs: add description of GVLK

gvlk/README.md

@@ -0,0 +1,21 @@
+# GVLKs
+
+> Generic Volume License Keys (GVLKs), sometimes referred to as the KMS client keys.
+
+Microsoft provides keys of different Windows versions on the [official website](https://learn.microsoft.com/en-us/windows-server/get-started/kms-client-activation-keys), where data in different languages will be crawled, and json data will be exported after sorting.
+
+Running the following command will automatically crawl and output to `raw.json`, you can specify the language in `config.yml`.
+
+```bash
+$ ./fetch.py
+```
+
+Since Microsoft basically uses machine translation in other languages, manually repair the content in `raw.json` and save it in `data.json`.
+
+Then run the following command, the final data will be exported, and it will be saved in the `../assets/gvlk/` directory by default. The specific order can be specified in `config.yml`.
+
+```bash
+$ ./release.py
+```
+
+Because the GVLKs will be updated with Microsoft's iterations, this working directory will always be updated.