Add to wiki/docs on new plugins

[okolehao]

Hi we added a new plugin check for Cabot that allows Cabot to create something similar to https://deadmanssnitch.com/ . It uses redis keys to check for background jobs/processes that fail to check in within a specific interval. Also unlike Deadmansnitch it works with much more granular intervals down to seconds or even larger ones like days.

https://github.com/objectstoragesolutions/cabot-check-tattletrail