JupyterLab extensions such as the git and github extension are Lab centric and build functionality into various palettes and JupyterLab IDE toolbars etc, but for document centric working in notebook (RetroLab as was), controls need to be added to the notebook app.
Are there any examples out there a simple notebook-centric JupyterLab extension demonstrating any git integration (eg even something as simple as a commit toolbar button (with a popup for the commit message)?