Notifications when data added to monitor plots

[stscijgbot-jwql]

Issue JWQL-205 was created on JIRA by Bryan Hilbert:

From the JWQL user survey:

Implement automated emails/notifications when new data are added to monitor plots.
Maybe we could have a dedicated slack channel for this? Or set up a new email distribution list?

It would be helpful if the notifications were instrument and monitor specific.