What would HN use in this case?
Even if you have to describe everything, what’s wrong with a high-level description that gives links to your code repository for “every minimal aspect”? That at least has some chance of still being correct six months from now.
And that’s ignoring the remark “This documentation will be consumed by […] stakeholders who are not tech-savvy.”
Describing every minimal aspect of processes, databases, scripts, functions and API endpoints to them is madness.
Secondly, hire a technical writer.