doc(lib): comments for some API

lib/src/platforms/android/models/nearby_device.dart

@@ -134,6 +134,9 @@ class NearbyAndroidDevice extends NearbyDevice {
   }
 }
 
+///
+/// Implementation of [NearbyDeviceMapper] for Android.
+///
 class NearbyAndroidMapper implements NearbyDeviceMapper {
   @override
   List<NearbyDevice> mapToDeviceList(dynamic value) {

lib/src/platforms/android/nearby_android_service.dart

@@ -19,6 +19,10 @@ class NearbyAndroidService extends NearbyService {
     return _socketService.state;
   }
 
+  ///
+  /// The connection information of a Wi-Fi p2p group connection
+  /// from the socket service.
+  ///
   NearbyConnectionAndroidInfo? get connectionInfo {
     return _socketService.connectionInfo;
   }

lib/src/platforms/ios/models/nearby_device.dart

@@ -69,6 +69,9 @@ class NearbyIOSDevice extends NearbyDevice {
   }
 }
 
+///
+/// Implementation of [NearbyDeviceMapper] for IOS.
+///
 class NearbyIOSMapper implements NearbyDeviceMapper {
   @override
   List<NearbyDevice> mapToDeviceList(dynamic value) {

lib/src/types/communication_channel_data.dart

@@ -80,6 +80,10 @@ class NearbyAndroidCommunicationChannelData {
   /// Listener of events that come to the server.
   ///
   final ValueChanged<HttpRequest>? serverListener;
+
+  ///
+  /// The port on which the socket will be created.
+  ///
   final int port;
 
   @override