ingconti/iOS17_ObservableLibraryView

new iOS17 Observable, rewritten fro Apple code for iOS17.

iOS17_ObservableLibraryView

new iOS17 Observable, rewritten fro Apple code for iOS17.

Simnply copy && paste from Apple WWWDC2023 code here:

https://developer.apple.com/documentation/swiftui/migrating-from-the-observable-object-protocol-to-the-observable-macro

but as bonus, inserted "Add" book button.