docs: replace .gitlab-ci.yml example with more reliable and faster ci job (...

Peter

2024-07-01 5926d3f803606d86129ed658147e66986d15fba8

 Dockerfile

New file
@@ -0,0 +1,11 @@
FROM node:20-slim as builder
WORKDIR /usr/src/app
COPY package.json .
COPY package-lock.json* .
RUN npm ci

FROM node:20-slim
WORKDIR /usr/src/app
COPY --from=builder /usr/src/app/ /usr/src/app/
COPY . .
CMD ["npx", "quartz", "build", "--serve"]