Context

This repo demonstrates a problem I'm having with Quarto and GitHub Pages.
Structure of the repo includes a code directory -- stubbed out for this example but suffice it to say that a main use-case for me is going to be having repos with non-trivial amounts of code, along with docs documenting that code.
Structure of the repo also includes a docs-source directory -- which is also stubbed out for this example but the idea is that a code repo will have documentation source in it which will go here.
I'm following https://quarto.org/docs/websites/publishing-websites.html#github-pages

The problem

GitHub Pages requires us to publish docs from the docs subdir of the repo, or the root of the repo -- no other choices
docs-source/_quarto.yml lets me specify output-dir: _site
If I do that then quarto preview and/or quarto render within docs-source both work fine. But they do not put docs where GitHub Pages wants them, i.e. in docs
If I instead put output-dir: ../docs in my docs-source/_quarto.yml then quarto preview and quarto render both appear to do nothing.
Also when I touch .nojekyll per the docs, regardless GitHub Pages is asking me to "choose a theme" for Jekyll.

How can I configure _quarto.yml to write doc artifacts into the docs directory which GitHub Pages requires?