message: docs(List): add en FAQ
diff: @@ -231,3 +231,62 @@ The component provides the following CSS variables, which can be used to customi
  | --van-list-text-font-size | _var(--van-font-size-md)_ | - |
  | --van-list-text-line-height | _50px_ | - |
  | --van-list-loading-icon-size | _16px_ | - |
  +
  +## FAQ
  +
  +### How does List component work?
  +
  +List will listen to the scroll event of the browser and calculate the position. When the distance between the bottom of the list and the visible area is less than `offset`, the List component will trigger a `load` event.
  +
  +### Why does the load event triggered immediately after mounted?
  +
  +A load event will be triggered immediately to load the first screen data. This feature can be disabled by the `immediate-check` prop.
  +
  +### Why does the load event triggered continuously?
  +
  +If the amount of data loaded in one request is too small, the List will continue to trigger the `load` event until the content fills the screen or the data is fully loaded.
  +
  +Therefore, you need to adjust the amount of data per request. Ideally, the amount of data per request should be able to fill the height of one screen.
  +
  +### What is the meaning of loading and finished?
  +
  +`List` has three states, understanding these states will help you use the component:
  +
  +- `loading = false`: Not in loading. The component will detect whether to trigger the `load` event according to the scroll position (if the content of the list is less than one screen, it will be triggered directly).
  +- `loading = true`: During loading. Indicating that an request is being sent, and the `load` event will not be triggered.
  +- `finished = true`: Loading is complete. No `load` will not be triggered.
  +
  +After each request, you need to manually set `loading` to `false`, indicating the end of loading.
  +
  +### Always trigger loading after using float layout?
  +
  +If you use the float layout on the content, you can add the `van-clearfix` class to the container to clear the float, so that the List can get the element position correctly.
  +
  +```html
  +<van-list>
  + <div class="van-clearfix">
  + <div class="float-item" />
  + <div class="float-item" />
  + <div class="float-item" />
  + </div>
  +</van-list>
  +```
  +
  +### Always trigger loading after setting overflow on html and body?
  +
  +If the `overflow-x: hidden` style is set on the html and body tags, it will cause the List to always trigger loading.
  +
  +```css
  +html,
  +body {
  + overflow-x: hidden;
  +}
  +```
  +
  +The reason is that when an element is styled with `overflow-x: hidden`, the element's `overflow-y` will be set to `auto` by the browser, instead of the default value of `visible`, causing the List can not determine the scroll container correctly. The workaround is to remove this style, or add the `height: 100%` style to the html and body tags.
  +
  +### Always trigger loading when the direction prop is set to up?
  +
  +Setting the `direction` prop to up will trigger the loading of the List component when the scrollbar is at the page top.
  +
  +When using this prop, it is recommended to scroll the scroll bar to the page bottom after each data request is completed.
  