message: create-app: sync backend Dockerfile
diff: @@ -2,8 +2,15 @@ FROM node:12
  WORKDIR /usr/src/app
  -COPY . .
  +# Copy repo skeleton first, to avoid unnecessary docker cache invalidation.
  +# The skeleton contains the package.json of each package in the monorepo,
  +# and along with yarn.lock and the root package.json, that's enough to run yarn install.
  +ADD yarn.lock package.json skeleton.tar ./
  RUN yarn install --frozen-lockfile --production
  +# This will copy the contents of the dist-workspace when running the build-image command.
  +# Do not use this Dockerfile outside of that command, as it will copy in the source code instead.
  +COPY . .
  +
  CMD ["node", "packages/backend"]
  