add command to resume last x messages

[vinibgoulart]

• [ ] use fetchMessages
• [ ] https://docs.wwebjs.dev/Chat.html#fetchMessages
• [ ] new command !resume-qty <x>
• [ ] get the last <x> messages and make a prompt for gpt api

[2yuri]

@vinibgoulart I can do that! can you assign it to me?