Feature request: get notified if an http code changes

Right now, the only options are to be notified of the error every update, or ignore them. Among the sites that I follow are a few stores that will close for a day or two before they add new products and I want to find out when the store goes down and back up without being constantly alerted while it's down.

If there's a HTTP status code, you can use the command watcher with a URL like this:

curl -s -I https://example.org | head -n1