add useImperativeHandle explanation comment

src/components/Hoverable/index.js

@@ -119,6 +119,7 @@ function InnerHoverable({disabled, onHoverIn, onHoverOut, children, shouldHandle
         }
     }, [disabled, isHovered, onHoverIn, onHoverOut]);
 
+    // Expose inner ref to parent through outerRef. This enable us to use ref both in parent and child.
     useImperativeHandle(outerRef, () => ref.current, []);
 
     const child = useMemo(() => React.Children.only(mapChildren(children, isHovered)), [children, isHovered]);