V0.1.0

• Presentation and navigation can now be combined into a single routes array, removing the need for separate PStack and NStack. The new Router can handle both.
• Convenience methods are now extensions on Array, with no more need for NFlow or PFlow, simplifying state management.
• Large-scale navigation updates can now be made within a withDelaysIfUnsupported call, and will be broken down into smaller updates that SwiftUI supports. This works around a limitation in SwiftUI that only allows one screen to be pushed, presented or dismissed at a time.
• The view builder closure for creating screens can now provide a binding to the screen so that screens can mutate their state within the routes array.
• A new showing function makes it easy to have a fixed root screen which shows zero or more routes.