It’s not really about the tools, we have plenty of tools, plain text, markdown, latex, web pages. Putting content to readable format is the easy part.

The hard part is knowing what to put down and how to organize it, and making sure that your documented explanations are actually understandable.

Particularly when you want to get traction going you might really want conversations to help you understand where the project needs fixing versus how documentation needs fixing and get a sense for what documentation might be helpful.