Update headers and clean up imports

client/hooks/useInterval.ts

@@ -1,3 +1,8 @@
+/**
+ * A collection of popular layouts and patterns made with CSS (https://csslayout.io)
+ * (c) 2019 - 2020 Nguyen Huu Phuoc <https://twitter.com/nghuuphuoc>
+ */
+
 import { useEffect } from 'react';
 
 const useInterval = (callback: () => void, delay?: number) => {