Workflow is triggered when a note is added to a contact. You can do it on the contact card or by means of action Add note.
This event has no additional settings.
Go to AUTOMATION PROCESSES => WORKFLOW
From the list of the elements in Workflow choose Event => Added note to contact
Example: A note has been added to the contact with information that somebody contacted with the user, thanks to this event the Workflow process is triggered towards this user.
IMPORTANT: Modifications made in CRM => Manage Contacts do not trigger rules.