Deprecate what the API no longer has

Methods (per the API changelog and schema 0.0.33):
- getChats(): GET /chats is not supported since June 2026
- getChatByLink(), deleteChat(): no longer documented, absent from
  the schema
- addMembers(): POST /chats/{chatId}/members is limited since
  9 September 2026 and removed on 30 September 2026

Models and enums absent from schema 0.0.33: the chat inline button,
reply buttons and ReplyButtonType, Intent, MessageChatCreatedUpdate
and its handlers, Chat::$chatMessageId.

Only @deprecated tags and docs; nothing is removed, so existing code
keeps working until a major release. README coverage map updated.

src/UpdateDispatcher.php

@@ -284,6 +284,8 @@ final class UpdateDispatcher
     /**
      * A convenient alias for addHandler(UpdateType::MessageChatCreated, $handler).
      *
+     * @deprecated message_chat_created is not in the Bot API schema since 0.0.33.
+     *
      * @param callable(Models\Updates\MessageChatCreatedUpdate, Api): void $handler
      *
      * @return $this