Configure Initial Layout without Binder

I’m distributing some data and code with a JupyterLab interface. I want to make sure that when my users open JupyterLab (via jupyter-lab) that they will get the view I want them to have. Namely, I want one tab open of the README.md file in markdown preview mode—not in editor mode.

There was an answer to a similar question a couple of years ago. That answer suggested the use of workspaces, but that was for distributing via binder; I’m not using binder. I’m having users download the code/data and running JupyterLab on their own machine. I’ve tried the answer in the previous question and it didn’t quite solve the issue for me. I like the idea of a workspace, but I can’t figure out how to make it work on a local machine.