message: Fixed environment variable name
diff: @@ -60,7 +60,7 @@ Rerun the build and start the container; it should take much less time now:
  cd ../crates-build-env/linux
  docker build --tag build-env .
  cd ../../docs.rs
  -docker-compose run -e DOCS_RS_LOCAL_DOCKER_IMAGE=build-env \
  +docker-compose run -e DOCSRS_DOCKER_IMAGE=build-env \
  -e RUST_BACKTRACE=1 \
  -v "$YOUR_CRATE":/opt/rustwide/workdir \
  web build crate --local /opt/rustwide/workdir
  