Fix issue with the app blocking access to the desktop

It seems like the native SwiftUI window is there even if not shown and somehow it sometimes consumes the mouse events.

Fixes #10

Color Picker/AppState.swift

@@ -75,6 +75,9 @@ final class AppState: ObservableObject {
 		)
 
 		DispatchQueue.main.async { [self] in
+			// Make the invisible native SwitUI window not block access to the desktop.
+			NSApp.windows.first?.ignoresMouseEvents = true
+
 			setUpEvents()
 			showWelcomeScreenIfNeeded()
 		}