I can't seem to open the plugin code in XCode. From my IDE (Android Studio) I can open the iOS example project in XCode but not the plugin code. I can open the Swift files in XCode but adding new files does not seem to have effect (I'm assuming this is because they need to be referenced to a project or workspace). Some documentation on how to setup the development environment (for iOS) would be great.

Also, the contribution guide links to the install process documentation in the original mapbox repository (which has recently been archives).