Heads-up: The next major version (5.0) will drop CocoaPods + Carthage support

Since the Swift Package Manager is now integrated into Xcode, all of my open source projects will stop supporting CocoaPods + Carthage starting with their next major version, which for Files will be `5.0`. There's no set timeline for when Files `5.0` will be released, it might take months (or even years), but I just want to give all users who depend on Files using either of those two package managers a heads-up so that you can plan accordingly.