I don’t know the product, company or broader community enough as to say what the standards and expectations are – I simply inherited quite a lot of pipelines where CircleCI plays a central role. So, I’m not sure if I’m the right person to answer this.
Nevertheless, I prefer code examples to be self-contained (to work as-is), so I’d start with places identified by something like this:
git clone git@github.com:circleci/circleci-docs.git
fgrep -Rl 'circleci/postgres' circleci-docs
And make sure that all the examples work.