add A11y (#48)

Co-authored-by: Oguz Yuksel <oguz.yueksel@teufel.de>

Sources/FoundationExtensions/A11y/AccessibilityIdentifiable.swift

@@ -0,0 +1,3 @@
+// Copyright © 2023 Lautsprecher Teufel GmbH. All rights reserved.
+
+public protocol AccessibilityIdentifiable: TypePathConvertible { }

Sources/FoundationExtensions/A11y/AccessibilityIdentifier.swift

@@ -0,0 +1,28 @@
+// Copyright © 2023 Lautsprecher Teufel GmbH. All rights reserved.
+
+/// A namespace for accessibility identifiers.
+///
+/// You could declare A11Y IDs like this
+/// ```
+/// extension AccessibilityIdentifier {
+///     enum HomeScreen: AccessibilityIdentifiable {
+///        enum MusicView: AccessibilityIdentifiable {
+///            case sectionHeader
+///            case recentlyPlayedScrollview
+///        }
+///
+///        enum MiniPlayer: AccessibilityIdentifiable {
+///            case muteButton
+///            case coverImage
+///        }
+///     }
+/// }
+/// ```
+/// Thanks to the TypePathConvertible conformance, you can use it on your views:
+/// ```
+/// Text("Podcasts")
+/// .accessibilityIdentifier(AccessibilityIdentifier.HomeScreen.MusicView.sectionHeader.typePath)
+/// ```
+/// which adds the A11Y ID "MyApp.AccessibilityIdentifier.HomeScreen.MusicView.sectionHeader" to the View.
+///
+public enum AccessibilityIdentifier: AccessibilityIdentifiable { }