DeviceDiscoveryExtension

1. Essentials

   Covers Discovering a third-party media-streaming device, Media Device Discovery Extension.

2. Extension

   Covers DDDiscoveryExtension, DDDiscoverySession, DDDiscoveryExtensionConfigurationProtocol.

3. Life cycle

   Covers DDDeviceEvent, DDDeviceEvent.EventType, DDEventTypeToString(_:), DDEventHandler.

4. Device information

   Covers DDDevice, DDDevice.Category, DDDeviceState, DDDeviceCategoryToString(_:).

5. Errors

   Covers DDError, DDError.Code, DDErrorHandler, DDErrorOutType.

6. Reference

   Covers DeviceDiscoveryExtension Enumerations.

Each section links to the official page. Titles and summaries by Extra Credit; the docs belong to their authors.