Update examples using Docker Compose

[dreglad]

Pull Request Description

This PR updates the docker-compose and event-driven-architecture example README files to reflect updated commands and practices, along with minor text adjustments.

Details / Rationale

1. Update to Docker Compose v2 Commands:

   • The README files previously used Docker Compose v1 commands (the standalone docker-compose command), which has passed its end-of-life. It has now been replaced by the built-in docker compose subcommands (removing the dash from docker-compose) and eliminated Docker Compose as a separate requirement since it is included with Docker.

2. Replace docker system prune with docker compose down:

   • The previous instructions suggested using docker system prune --volumes to clear the environment. This command has been replaced with docker compose down --volumes. The earlier is potentially destructive as it affects all other containers and volumes, not just those related to the Apicurio Registry setup as intended. docker compose down is safer and the appropriate command for stopping and removing containers, networks, and volumes defined in the Docker Compose file without impacting other Docker resources on the user's system.

[apicurio-bot]

Thank you for creating a pull request!

Pinging @andreaTP to respond or triage.

[EricWittmann]

Thanks for the updates! Much appreciated.