helps to monitor AH delivery
user -> help user -> addme => bot: get chatId, postcode, save to db user -> removeme => bot: remove chatId, postcode from db
bot -> by trigger check available deliveries. If something is available, send a message
ah-bot internally has a channel with events.
telegram pushes an event from user telegram listens to new message event
pubsub pushes an event for scan pubsub listens to scan requests from external pubsub
ah-bot listens to events when ah-bot gets an help,addme, removeme events -> message when ah-bot gets an scan event -> message