Seeking example project showing Swift Package Manager for building SwiftUI Multiplatform application. We're trying to take advantage of some of the enhancements introduced at WWDC 2020. We've successfully migrated our server application away from CocoaPods to SPM. The client has proven more resistant. We'd like to build a SwiftUI application targeting both iOS and macOS using the same build system as the server. Currently, it looks like multiplatform applications require an Xcode project file. Hopefully someone has seen documentation that we've missed or has come up with a clever solutions. Thanks.