androidx 库添加 jetpack

添加 viewpager2，功能验证ok

Merge remote-tracking branch 'origin/master'

Merge remote-tracking branch 'origin/master'

处理刷新后，导致数据不对的问题

Merge remote-tracking branch 'origin/master'

Update README.md

Merge remote-tracking branch 'origin/master'

Merge remote-tracking branch 'origin/master'

功能和说明文档增加完成