Feature: Telegram API integration for notifications

Description

We'd like to get notifications in Telegram groups & supergroups (a group with threads like discord server & channels). If I checked everything right, this functionality isn't supported now on the latest release version.

Proposed Solution(s)

I believe I might help with the implementation of the feature. I'm going to create a fork and try to implement it, and you might consider later on whether it's worth to be merged or not.