message: docs(faq): add FAQ doc
diff: # FAQ
  +
  +### Why can't BetterScroll scroll is failed when initialization?
  +
  +BetterScroll scrolling principle is that the height/width of the `content` element exceeds the height/width of the `wrapper` element. Also, if your content element contains images of a non-fixed size, you must call the `refresh()` method to ensure that the height is calculated correctly after the image has been loaded. There is also a situation where the form element exists on the page. After the keyboard is popped up, the palatable height of the page is compressed, causing `bs` to not work properly, and the `refresh()` method is still need to be called.
  +
  +### Why can't the click event in the BetterScroll area be triggered?
  +
  +By default, BetterScroll blocks the browser's native click event. If you want the click event to take effect, BetterScroll dispatches a click event and the `_constructed` of the event parameter is true. The configuration items are as follows:
  +
  +```js
  +import BScroll from '@better-scroll/core'
  +
  +let bs = new BScroll('./div', {
  + click: true
  +})
  +```
  +
  +### Why does my BetterScroll listen for the `scroll` hook and the listener doesn't execute?
  +
  +BetterScroll uses the `probeType` configuration item to decide whether to dispatch the `scroll` hook because there is some performance penalty. When the `probeType` is `2`, the event will be dispatched in real time. When the `probeType` is `3`, the event will be dispatched during the `momentum` animation. The recommended setting is `3`.
  +
  +```js
  +import BScroll from '@better-scroll/core'
  +
  +let bs = new BScroll('./div', {
  + probeType: 3
  +})
  +```
  +
  +### Slide used horizontal scrolling, found that vertical scrolling in the slide area is invalid?
  +
  +If you want to keep your browser's native vertical scrolling, you need the following configuration items:
  +
  +```js
  +import BScroll from '@better-scroll/core'
  +
  +let bs = new BScroll('./div', {
  + eventPassthrough: 'vertical'
  +})
  +```
  