Please contribute documentation changes to https://github.com/OpenMage/magento-lts/tree/main/docs which are rendered at https://docs.openmage.org
you can build the docs local with make by doing make html, which then puts the generated html in _build/html/.
To setup the local environment to build the html you need python(3) with pip.
you then can install the dependencies with
pip install -r requirements.txt
Its probably incomplete, please open an Issue if you have still problems to build the html.