docker-compose.yml: version is obsolete

[kannvess]

Obsolete attribute

When I was doing Part 2 Section 1 (Migrating to Docker Compose) I ran into an issue after running docker compose build with the given docker-compose.yml:

version: '3.8'

services:
  yt-dlp-ubuntu:
    image: <username>/<repositoryname>
    build: .

The first line of the ouput is WARN[0000] <pwd>/docker-compose.yml: `version` is obsolete. I looked it up on google and found a closed issue docker/compose#11628. The resolution is that the attribute version is not needed anymore and also, here's the docs section to back it up.