Add uniform note header + tag support to triage workflow

[davidwhittington]

What

During triage, optionally stamp notes with a uniform header and write tags into the note body.

Open design questions

• Tags written during triage (e.g. #archive, #promote) or note-type tags (#meeting, #idea)?
• nm stamp command to apply headers to existing notes, or only on promoted/extracted notes?
• Tag filtering in nm scan and nm status?

Related

• install_templates.applescript already defines 4 structured note templates (Account, Idea, Meeting, Project)
• Tags would complement the existing template headers