add plugin camera desktop

plugins/camera_desktop/lib/camera_desktop.dart

@@ -0,0 +1,9 @@
+/// A Flutter camera plugin for desktop platforms (Linux, macOS, Windows).
+///
+/// This plugin implements [CameraPlatform] from camera_platform_interface,
+/// allowing it to work seamlessly with the standard camera package.
+/// Users simply add camera_desktop as a dependency and the standard
+/// CameraController works on desktop automatically.
+library;
+
+export 'src/camera_desktop_plugin.dart';