Document Swift 6 and strict concurrency changes

Author: Zandor300

CHANGELOG.md

@@ -2,6 +2,14 @@
 
 ## Unreleased
 
+### New features
+
+- Add Swift 6 and strict concurrency support, including `Sendable` conformances for `Device` and its supporting types. ([#437](https://github.com/devicekit/DeviceKit/pull/437))
+
+### Breaking changes
+
+- Require main-actor access for UIKit-backed device properties, including `isPhone`, `isPad`, screen information, battery information, and orientation, and make `Device.identifier` read-only. The Xcode project now requires Swift 6, and the Xcode and Swift Package Manager watchOS deployment targets increase to watchOS 6.0. ([#437](https://github.com/devicekit/DeviceKit/pull/437))
+
 ### Maintenance
 
 - Simplify GYB device definitions with named feature parameters and defaults for unsupported features, preserving the generated Swift output. ([#508](https://github.com/devicekit/DeviceKit/pull/508))