Added new resource for refs (#3574)

src/data/roadmaps/react/content/103-rendering/103-refs.md

@@ -10,4 +10,5 @@ Visit the following resources to learn more:
 - [Manipulating the DOM with Refs](https://react.dev/learn/manipulating-the-dom-with-refs)
 - [Examples of using refs in React](https://www.robinwieruch.de/react-ref/)
 - [The Complete Guide to useRef() and Refs in React](https://dmitripavlutin.com/react-useref-guide/)
+- [What Exactly Are Refs? - React - CodeGuage](https://www.codeguage.com/courses/react/refs)
 - [Learn useRef in 11 Minutes - Web Dev Simplified](https://www.youtube.com/watch?v=t2ypzz6gJm0)