docs: vercel oss badge

Author: ariflogs

README.md

@@ -10,6 +10,12 @@ RetroUI is a retro-styled Tailwind CSS component library for modern web apps.
 
 ### [Contributing Guide](./CONTRIBUTING.md)
 
+<br />
+<br />
+<div>
+    RetroUI is part of the &nbsp;<a href="https://vercel.com/oss"><img alt="Vercel OSS Program" src="https://vercel.com/oss/program-badge.svg" /></a>&nbsp;<small><a href="https://vercel.com/blog/spring25-oss-program">(spring 2025 cohort)</a></small>
+</div>
+
 ## License
 
 [MIT](./LICENCE.md)