The history feature of a Notebook is a great way to show every change to the page. I find myself adding a markdown table at the top of library pages with a User, Version, Date, Desc for feature modification to get a quick summary idea of what has happened. I think this can be automated by adding Tagging, or Commit Comments to the history of a page. You probably would have to display the history and then be able to edit the metadata on any given change. Tag and Comment could be two options that you can add or edit. Then when a page is displayed, there could be a … option for History Summary and it would list just the Tag, Comment, Date, and all contributors between that Tag and the previous Tag in table format.