Add Support to SPM

[shshalom]

please add support to the swift package manager.

[Appracatappra]

Hi shshalom, I've taken scihant's excellent work on this library, made a SwiftUI version and released it as a Swift Package Manager Package https://github.com/Appracatappra/SwiftUIPanoramaViewer. Since I made so many changes that take it away from its initial design, I've released it as a new library instead of making a pull request on this one.