Remove confusing reset feature

[aralroca]

Fixes #41

Pre-released in 0.8.0-canary.1. (If you want to try it)

Remove the "reset" as the responsibility of the library. In this way:

Pros:

• Removing confusion as to what exactly the reset function did. Simplifying and making it easier to understand.
• Fewer things in memory. Thus it is not necessary to save the store + initialStore. Only the store. This improves performance for applications with very large stores.
• Tiniest. Supporting reset made it take up more bits.
• Removing a feature that did not add value to the library, since the same could be done with the setter.
• More flexibility to the user to reset with the setter where the user wants: last value, last value fetched to an API, initial value...

Cons:

• The user will be responsible for controlling the reset. That is, save the value in memory.

  Example:

  const [value, setValue] = useStore.value()
  const lastValue = useRef(value)
  
  // After some changes, is possible to reset with:
  setValue(lastValue.current)

  Another example:

   const initialStore = { count: 0 }
   export const { getStore } = createStore(initialStore)
   const [,setStore] = getStore()
  
   export const reset = () => setStore(initialStore)

   import { reset } from './store'
  
   function ResetStore() {
     return <button onClick={reset}>Reset store</button>
  }

[danielart]

Could you change it on examples folder? I could manage that if you want in an other pr I changed this on examples folder

[aralroca]

An extra pro 🙂:

• useStore proxy hook now is more familiar with React.useState.

[yathink3]

It make more sense now