fix(doc): update state-with-url-hash demo (#1687)

* fix(doc): update state-with-url-hash demo

* fix(doc): url-hash demo better code

docs/guides/connect-to-state-with-url-hash.md

@@ -9,13 +9,13 @@ If you want to connect state of a store to URL hash, you can create your own has
 
 ```ts
 import { create } from 'zustand'
-import { persist, StateStorage } from 'zustand/middleware'
+import { persist, StateStorage, createJSONStorage } from 'zustand/middleware'
 
 const hashStorage: StateStorage = {
   getItem: (key): string => {
     const searchParams = new URLSearchParams(location.hash.slice(1))
-    const storedValue = searchParams.get(key)
-    return JSON.parse(storedValue)
+    const storedValue = searchParams.get(key) ?? ''
+    return storedValue
   },
   setItem: (key, newValue): void => {
     const searchParams = new URLSearchParams(location.hash.slice(1))
@@ -37,12 +37,12 @@ export const useBoundStore = create(
     }),
     {
       name: 'food-storage', // unique name
-      getStorage: () => hashStorage,
+      storage: createJSONStorage(() => hashStorage),
     }
   )
 )
 ```
 
 ## CodeSandbox Demo
 
-https://codesandbox.io/s/silly-fire-gsjbc7?file=/src/App.tsx
+https://codesandbox.io/s/zustand-state-with-url-hash-demo-pn20n5?file=/src/store/index.ts