A similar approach I've been using recently and am so far really, really enjoying is to put all "conversation" into a dedicated "devlog" directory in the project root. We put everything in it: meeting notes, project status updates, memos, changelogs for every pull request, reviews, etc. Every file is markdown and named with a date prefix, a "nonce" for uniqueness, and a category (date.nonce.category.md). So you might have something like:
The file naming includes a small amount of ambiguity and a small opportunity for merge conflicts but in practice it's just not a problem. The best part of this workflow IMO is that it doesn't create a whole new workflow for communication, it treats high-quality async communication as part of the core (pull, read, commit, push, review) development workflow.
