Component Proposal (新组件建议集中在这里提 )

If you need a new component, comment here and attach screenshots, thanks.

如果有新组件需求，请在这里评论并附上实际例子截图。
- [ ] Off-canvas menus 侧边栏 #124 #139
- [x] Badge #124
- [ ] Uploader #139 不做封装，很难满足所有人需求，引入样式自己开发 https://github.com/airyland/vux/blob/v2/src/demos/Uploader.vue
或者使用 @greedying 开发的 [vux-uploaders](https://github.com/greedying/vux-uploader) #997
- [ ] Smart select #199
- [x] Image preview @nowui
- [x] swipeout #412
- [x] popover
- [ ] collapse #1117 @zerofront
- [ ] index-list #1882

`scroller`不是一个好的解决方式，如果只是为了Loadmore, 将独立提供loadmore组件
- [ ] Load more