Create and document an approach to using docker compose profiles to select major containers

This issue is prompted by the use of docker compose profiles to manage technology selection in the PR to integrate the RDF4J reasoner. Review created following comment:

_Observation:_ The KL driving style example docker compose relies on you always specifying the reasoner profile. For example `docker compose down` would not shutdown all containers, only the base ones. To shutdown all containers you need to use `docker compose --profile rdf4j down`. The example CLI commands shown in the README all meet that criteria.

I do not see it as a barrier to merging, but we could collectively discuss how to automate a default in the future. Docker provides mechanisms for this but we should collectively decide which to use.

_Originally posted by @slawr in https://github.com/COVESA/cdsp/pull/119#discussion_r3647306776_

The addition solved the issue of selection between RDFox and RDF4J but leaves some other aspects of general profile use unanswered. For example you must now specify the profile for all containers to be stopped using `docker compose down`.

The task is to collectively consider how to use profiles to handle high level technology selection. Particularly in the reference docker compose.

Rough task list:
- [ ] Agree approach
- [ ] Document approach