Prefer functional updates version in hooks documentation

Currently React hooks documentation at section Updating state is using a counter example for bot hooks and class based components. To recap:

In a class, we need to call this.setState() to update the count state:

  <button onClick={() => this.setState({ count: this.state.count + 1 })}>
    Click me
  </button>

In a function, we already have setCount and count as variables so we don’t need this:

  <button onClick={() => setCount(count + 1)}>
    Click me
  </button>

Although I can understand than this documentation must be simple and this example is really straightforward, isn't this a bad patter? Modifying state with a value based on old state?

The Functional update version is documented few pages after this example.

I'm wondering if:

• this example must be changed (although is probably the best type of example for state), or
• a warning box should be added to warn the user this is not the correct way to do.

To be more clear: I know there's nothing wrong with this specific example, but newcomers can quickly try to do something like calling setCount(count + 1) multiple times.

Inizia dalla sezione Updating state in hooks-state.html e confronta il relativo esempio del contatore con la sezione Functional updates in hooks-reference.html. Determina se l’esempio o un’avvertenza esplicativa affronta meglio gli aggiornamenti ripetuti basati sullo stato precedente; il lavoro è completo quando la documentazione guida chiaramente chi è alle prime armi senza contraddire l’esempio esistente.