Synchronous get / set?

Very helpful package! Thank you.

I'm using `ImmortalDB` with React to save some page state to local.
I would like to init a component's state by loading locally stored state, like:
```javascript
const MyComponent = () => {
const [state, setState] = useState(() => {
return ImmortalDB.get('key')
})
}
```

But `ImmortalDB.get` returns a Promise, so the above line would be `return await ImmortalDB.get('key')`.
And React's `useState` does not support async functions,
so a **synchronous** `get` would be very helpful