[LLC, Persistence] Add doc comments

Signed-off-by: Sahil Kumar <[email protected]>

packages/stream_chat_persistence/lib/src/entity/connection_events.dart

@@ -1,18 +1,25 @@
 import 'package:moor/moor.dart';
 import 'package:stream_chat_persistence/src/converter/map_converter.dart';
 
+/// Represents a [ConnectionEvents] table in [MoorChatDatabase].
 @DataClassName('ConnectionEventEntity')
 class ConnectionEvents extends Table {
+  /// event id
   IntColumn get id => integer()();
 
+  /// User object of the current user
   TextColumn get ownUser => text().nullable().map(MapConverter<Object>())();
 
+  /// The number of unread messages for current user
   IntColumn get totalUnreadCount => integer().nullable()();
 
+  /// User total unread channels for current user
   IntColumn get unreadChannels => integer().nullable()();
 
+  /// DateTime of the last event
   DateTimeColumn get lastEventAt => dateTime().nullable()();
 
+  /// DateTime of the last sync
   DateTimeColumn get lastSyncAt => dateTime().nullable()();
 
   @override