add Credits

Author: bySabi

README.md

@@ -150,11 +150,18 @@ _afterAnimate = () => {
 };
 ```
 
-
 ## Example
 
 [react-scrollchor--example](https://github.com/bySabi/react-scrollchor/tree/example)
 
+## Credits
+
+### author
+* [@bySabi](https://github.com/bySabi)
+
+### top contributors
+* [@jeanchung](https://github.com/jeanchung)
+
 ## Contributing
 
 * Documentation improvement