Deep linking instruction may need an update

I'm trying to implement deep linking in my app but there are some inconsistencies between React Navigation's doc, React Native's and Android's which makes me feel confusing. For example, in https://reactnavigation.org/docs/en/deep-linking.html#android-1 it's talking about "Set launchMode of MainActivity to singleTask" with a link to the respective Android doc page, however there's no mentioning about this over there and the XML code snippet looks quite different; same is also true for the iOS section, the snippet given in https://reactnavigation.org/docs/en/deep-linking.html#ios-1 was outdated according to https://facebook.github.io/react-native/docs/linking

Someone in the know may wanna look into this and update the docs.

将 React Navigation 的深度链接页面与链接的 React Native、Android 和 iOS 文档进行比较，重点关注 issue 中提到的 launchMode 和平台代码片段。更新说明，使其与当前的平台指南一致，然后验证深度链接文档在各个章节之间保持一致。