Update README with contributor badge and features

Author: yash-pouranik

README.md

@@ -212,4 +212,10 @@ UrBackend is just getting started. Here’s what’s on the horizon:
 
 Want to see a feature? [Open an issue!](https://github.com/yash-pouranik/urbackend/issues)
 
+<a href="https://github.com/yash-pouranik/urbackend/graphs/contributors">
+  <img src="https://contrib.rocks/image?repo=yash-pouranik/urbackend" />
+</a>
+
+Made with [contrib.rocks](https://contrib.rocks).
+
 Built with ❤️ for **urbackend**