The Keynote/Numbers/Pages apps for iPhone have a Help modal view that is very neat. Firstly I would like to know the format in which the Help content is stored. The “Apple Help Book” format is used for the macOS apps, but which format is used for the iOS apps ? Secondly I would like to know which SwiftUI API is used to build such a Help modal view. Where to find a SwiftUI example that is based on the same storage format ?