Update CHANGELOG.zh-CN.md (#3423)
Update CHANGELOG.zh-CN.md (#3423)

新增 2.x 不兼容改动，”Popover 移除 overlay ，请使用 content。“
mitchelldemler/ant-design,elevensky/ant-design,ant-design/ant-design,zheeeng/ant-design,ant-design/ant-design,vgeyi/ant-design,vgeyi/ant-design,marswong/ant-design,mitchelldemler/ant-design,mitchelldemler/ant-design,elevensky/ant-design,liekkas/ant-design,waywardmonkeys/ant-design,RaoHai/ant-design,havefive/ant-design,havefive/ant-design,zheeeng/ant-design,zheeeng/ant-design,liekkas/ant-design,ant-design/ant-design,marswong/ant-design,zheeeng/ant-design,RaoHai/ant-design,marswong/ant-design,RaoHai/ant-design,marswong/ant-design,RaoHai/ant-design,elevensky/ant-design,hjin-me/ant-design,liekkas/ant-design,vgeyi/ant-design,icaife/ant-design,hjin-me/ant-design,hjin-me/ant-design,hjin-me/ant-design,elevensky/ant-design,icaife/ant-design,vgeyi/ant-design,mitchelldemler/ant-design,ant-design/ant-design,waywardmonkeys/ant-design,icaife/ant-design,waywardmonkeys/ant-design,icaife/ant-design,liekkas/ant-design,havefive/ant-design,havefive/ant-design