docs: Add GitHub release badge to README

Author: weilycoder

README.md

@@ -1,5 +1,7 @@
 # Jiyu_udp_attack
 
+[![GitHub release](https://img.shields.io/github/release/weilycoder/Jiyu_udp_attack.svg)](https://github.com/weilycoder/Jiyu_udp_attack/releases/latest)
+
 利用极域电子教室的 udp 包攻击学生机。
 
 对这方面技术的了解来自 [ht0Ruial/Jiyu_udp_attack](https://github.com/ht0Ruial/Jiyu_udp_attack/)。