<demo>

### Closable

Display a close button to allow to close the alert. Also, it is a smooth unmount when the alert is closed.

```jsx live
<>
  <Alert closable>Info alert</Alert>
  <Alert closable type="success">Success alert</Alert>
  <Alert closable type="warning">Warning alert</Alert>
  <Alert closable type="error">Error alert</Alert>
</>
```

</demo>
