What do you use to document your automation process?

I built a excel report that stakeholders use frequently. The SQL code is nested in Powerquery, and uses a combination of VBA / Python that does the admin task (kick off Powerquery, makes the file, compiles it into an email, etc) paired with task scheduler. Is there a useful avenue I can use to map it all out in the event I need to pass it off to someone else? Currently my map is on a notebook paper