Support for SPM on iOS

[abegehr]

Is your feature request related to a problem? Please describe.
The plugin is not usable on CapacitorJS projects using SPM instead of CocoaPods.

Describe the solution you'd like
Add support for SPM: https://capacitorjs.com/docs/ios/spm - since this package has no dependencies in the podfile, shouldn't be more than adding a Package.swift file.

Describe alternatives you've considered
none

[AlistairMRoss]

Any update on this?