This is the relevant part, to me. Can we do this documentation process JIT when someone asks about it? Maybe even convert the dialogue (in chat) or transcript of the conversation into the documentation.
When a collaborator or client talks to me or when I think about something, then I open a markdown file (first often just a notes.md) and just write in bullet points, and gradually organize it into categories.
I put these in version control as well since a while.
Thought experiment: if something is not worth writing down, is it worth discussing?
Writing things down in a way that can be consumed by others is usually significantly more work than discussing that same thing live (whether in text or verbally). As such, I would say that the answer is obviously yes.