message: Update Docker host build documentation with updated default Dockerfile
diff: @@ -60,15 +60,16 @@ FROM node:14-buster-slim
  WORKDIR /app
  -# 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 packages/backend/dist/skeleton.tar.gz ./
  +COPY yarn.lock package.json packages/backend/dist/skeleton.tar.gz ./
  +RUN tar xzf skeleton.tar.gz && rm skeleton.tar.gz
  RUN yarn install --frozen-lockfile --production --network-timeout 300000 && rm -rf "$(yarn cache dir)"
  # Then copy the rest of the backend bundle, along with any other files we might want.
  -ADD packages/backend/dist/bundle.tar.gz app-config.yaml ./
  +COPY packages/backend/dist/bundle.tar.gz app-config.yaml ./
  +RUN tar xzf bundle.tar.gz && rm bundle.tar.gz
  CMD ["node", "packages/backend", "--config", "app-config.yaml"]
  ```
  