watch: the watch command keeps running and polling the notifications endpoint, if new notifications are detected print them stdou. In this mode the program can only be stopped with CTRL+C
for testing purposes, create two accounts on TESTNET version of hodlhodl https://hhtestnet.com/ , create a fake listing with one account, and accept offer with the other account and send messages to generate notifications for the first account. you also have to put the xmpp accounts in the config file.