Co-authored-by: Stanislav Lashmanov <slashmanov@gitlab.com>
Under the hood, `$subscribe()` uses Vue's `watch()` function. You can pass the same options as you would with `watch()`. This is useful when you want to immediately trigger subscriptions after **each** state change:
```ts{4}
-cartStore.$subscribe((state) => {
+cartStore.$subscribe((mutation, state) => {
// persist the whole state to the local storage whenever it changes
localStorage.setItem('cart', JSON.stringify(state))
}, { flush: 'sync' })