add REUSE status to readme

Author: h4x3rotab

README.md

@@ -6,6 +6,7 @@
 
 [![GitHub Stars](https://img.shields.io/github/stars/dstack-tee/dstack?style=flat-square&logo=github)](https://github.com/Dstack-TEE/dstack/stargazers)
 [![License](https://img.shields.io/github/license/dstack-tee/dstack?style=flat-square)](https://github.com/Dstack-TEE/dstack/blob/master/LICENSE)
+[![REUSE status](https://api.reuse.software/badge/github.com/fsfe/reuse-tool)](https://api.reuse.software/info/github.com/fsfe/reuse-tool)
 [![Telegram](https://img.shields.io/badge/Community-blue?style=flat-square&logo=telegram&logoColor=fff)](https://t.me/+UO4bS4jflr45YmUx)
 [![Ask DeepWiki](https://deepwiki.com/badge.svg)](https://deepwiki.com/Dstack-TEE/dstack)