feat(SW-441): Implemented useScrollSpy hook

hooks/useHash.tsx

@@ -4,10 +4,13 @@ import { useParams } from "next/navigation"
 import { useEffect, useState } from "react"
 
 function getHash() {
-  return typeof window !== "undefined" ? window.location.hash : undefined
+  if (typeof window === "undefined" || !window.location.hash) {
+    return undefined
+  }
+  return window.location.hash.split("#")[1]
 }
 
-function useHash() {
+export default function useHash() {
   const [isClient, setIsClient] = useState(false)
   const [hash, setHash] = useState(getHash())
   const params = useParams()
@@ -19,5 +22,3 @@ function useHash() {
 
   return isClient ? hash : null
 }
-
-export default useHash