How it goes in practice.
Set up the folder
Give each client a folder for meeting notes, the documents they sent, decisions and the deliverable in progress.
Record decisions
Write each decision as a short note with the reason and the date, and tag it #decision to list them across every client.
Share the engagement
Share the client's folder with a colleague as an editor, or with the client as a viewer. It is encrypted to the people you invite, and edits made at the same time merge.
Pick it up again
After two weeks away, read the decision notes and the history of the deliverable to see where things stand.