The Docker example in the README doesn't work

[willywongi]

Ciao!
I used to have a docker image with dart-sass for building a personalized version of Bootstrap, but yesterday it updated itself and stopped working. I checked the Dockerfile example from the README, but it doesn't work.
After some trials and errors I found out two issues.

• There's a typo in the Protocol Buffer image name: it's bufbuild/buf, not buildbuf/buf.
• The buf command doesn't work; I added COPY --from=buf /usr/local/bin/buf /usr/local/bin/ to make it run.

👋