Missing Dockerfile in ./course/module-1

[HalberdOfPineapple]

I tried to build this project from scratch incrementally but found the Github Action will fail in the job build because the Dockerfile is missing in ./course/module-1:

buildx failed with: ERROR: failed to solve: failed to read dockerfile: open Dockerfile: no such file or directory

I am wondering whether this is your mistake, or should I create a Dockerfile by myself based on docker-compose.yml? Sorry I am just a fresher in CI/CD and this may sound like a naive question.