Additional property dockerproxy is not allowed
Noobie here. I tried copy&paste to deploy but got the below error. Seemed I missed a version and services attribute in the docker compose but didn't know. Maybe include in the example?

Where are you trying to deploy this?
I was able to reproduce this. I assume the OP means that he created a "docker-compose.yml" file on the host system, pasted the example docker-compose code and then attempted to run it such as:
sudo docker compose up -d
This may be a candidate for a PR to fix the info but the solution is just to make sure you add the services: header, this is standard with docker-compose files but easy to forget.
Just add
services:
above dockerproxy: and indent subsequent lines accordingly.