message: docs(wheel): optimize docs
diff: @@ -138,6 +138,24 @@ BetterScroll combined with the Wheel plugin is just the JS logic part of the Pic
  ## Instance Methods
  +:::tip
  +All methdos are proxied to BetterScroll instance, for example:
  +
  +```js
  +import BScroll from '@better-scroll/core'
  +import Wheel from '@better-scroll/wheel'
  +
  +BScroll.use(Wheel)
  +
  +const bs = new BScroll('.bs-wrapper', {
  + wheel: true
  +})
  +
  +bs.getSelectedIndex()
  +bs.wheelTo(1, 300)
  +```
  +:::
  +
  ### getSelectedIndex()
  - **Returns**: The index of the currently selected item, the subscript starts from 0
  