Checklist

• I believe the idea is awesome and would benefit the framework
• I have searched in the issue tracker for similar requests, including closed ones

Description

Hydrogram does not currently support or handle the my_chat_member update event, which—according to the Official Bot API documentation—occurs when the bot’s chat membership status changes:

The bot’s chat member status was updated in a chat. For private chats, this update is received only when the bot is blocked or unblocked by the user.

Handling this event is essential for use cases such as purging chat data when the bot is blocked, and for sending a greeting message when the bot is added to a channel or group. Therefore, I request the addition of a dedicated handler and decorator for the my_chat_member update.

Thank You!
(that’s enough yapping, man.)