Each folder will have settings with "notifications to Telegram"
settings:
API_KEY _______
CHAT_ID _______
TEXT
Text Settings:
-+ count of added/deleted files after sync end
-+ names of added deleted files afted sync end
-+ start/end time of sync
Script to notify:
https://api.telegram.org/API_KEY/sendMessage?chat_id=CHAT_ID&text=TEXT
Notification script can be open to modify by user. So you can add more settings fields and user can use his own API to notify (whatasp viber line or something else)