adjust to new workflow

Dockerfile

@@ -2,7 +2,9 @@ FROM docker.io/hugomods/hugo:latest AS build
 WORKDIR /src
 COPY . .
 RUN git submodule update --init --recursive --progress
-RUN hugo
+ARG HUGO_ENV=production
+ENV HUGO_ENV=${HUGO_ENV}
+RUN hugo --environment $HUGO_ENV --minify
 
 FROM nginx:alpine
 COPY --from=build /src/public /usr/share/nginx/html