chore: add comment to _private in realtime_channel

Author: dshukertjr

packages/realtime_client/lib/src/realtime_channel.dart

@@ -32,6 +32,7 @@ class RealtimeChannel {
   @internal
   final RealtimeClient socket;
 
+  /// Defines if the channel is private or not and if RLS policies will be used to check data
   late final bool _private;
 
   RealtimeChannel(

packages/realtime_client/lib/src/types.dart

@@ -148,7 +148,7 @@ class RealtimeChannelConfig {
   /// [key] option is used to track presence payload across clients
   final String key;
 
-  /// defines if the channel is private or not and if RLS policies will be used to check data
+  /// Defines if the channel is private or not and if RLS policies will be used to check data
   final bool private;
 
   const RealtimeChannelConfig({