Add Swift AppDelegate setup instructions for deep linking#1428

satya164 merged 4 commits intoreact-navigation:mainreact-navigation/react-navigation.github.io:mainfrom

kleviss:feat/deep-linking-docs-add-swift-appdelegatekleviss/react-navigation.github.io:feat/deep-linking-docs-add-swift-appdelegateCopy head branch name to clipboard