message: docs(Toast): add loadingType demo
diff: @@ -24,6 +24,12 @@ Toast.loading({
  message: 'Loading...',
  forbidClick: true
  });
  +
  +Toast.loading({
  + message: 'Loading...',
  + forbidClick: true,
  + loadingType: 'spinner'
  +});
  ```
  ### Success/Fail
  @@ -47,12 +53,12 @@ Toast({
  });
  ```
  -### Advanced Usage
  +### Update Message
  ```javascript
  const toast = Toast.loading({
  duration: 0, // continuous display toast
  - forbidClick: true, // forbid click background
  + forbidClick: true,
  loadingType: 'spinner',
  message: '3 seconds'
  });
  