Merge refs hook

The goal of this package is to make it easy to have a component which requires a ref but also wants to support forwarding refs.

Example

const myComponent = React.forwardRef((props, ref) => {
    const local = React.createRef()

    // Create local ref
    useHookWhichNeedsRef(local)

    // mergeRefs allows you to pass both your local, and forwarded ref
    // and gives you a ref back which can be passed down
    const mergedRef = useMergeRefs(ref, local)

    // You can now use mergedRef and both forwarded and local ref will
    // be updated
    return <div ref={mergedRef} />
})