Update README.md

Added the license shield

README.md

@@ -3,7 +3,7 @@
 <h3 align="center">The Internet OS! Free, Open-Source, and Self-Hostable.</h3>
 
 <p align="center">
-    <img alt="GitHub repo size" src="https://img.shields.io/github/repo-size/HeyPuter/puter"> <img alt="GitHub Release" src="https://img.shields.io/github/v/release/HeyPuter/puter?label=latest%20version">
+    <img alt="GitHub repo size" src="https://img.shields.io/github/repo-size/HeyPuter/puter"> <img alt="GitHub Release" src="https://img.shields.io/github/v/release/HeyPuter/puter?label=latest%20version"> <img alt="GitHub License" src="https://img.shields.io/github/license/HeyPuter/puter">
 </p>
 
 <p align="center">