Here is the commit github.com/…/b3bd2afd6af18e71048ade7e82b541ff903a…
It creates the docker file and updates the docs to (among other things) point to the he file, the old being raw.githubusercontent.com/…/docker-compose.yml.
I wonder why it does not point to the main repo. The PR does not discuss the it. github.com/LemmyNet/lemmy-docs/pull/315