Overhaul docker documentation and fix minor bugs

[ebr]

Summary

• Adds instructions on running the official images to the main README, to the docker/README.md, and to the mkdocs documentation
• changes the name of docker-compose profile to invokeai-cuda, as suggested in Docker compose changes #6043
• ensures that the chown command in docker entrypoint script does not break on read-only filesystems

Related Issues / Discussions

Closes #6264

QA Instructions

I tested following these docs on a Linux system, but some testing on Windows with WSL would be helpful.

1. Try the docker run commands from the README, including working directory persistence. Try mounting an existing InvokeAI root dir into the container, as described in the README.
2. Test the run.sh script and docker compose commands

Merge Plan

Merge when approved

Checklist

• The PR has a short but descriptive title, suitable for a changelog
• Documentation added / updated (if applicable)

[psychedelicious]

LGTM!

I'd prefer a link to the docker docs in root repo README, rather than partially duplicating the docker docs. More to keep updated and longer README. Will leave that up to you though, not a big deal either way. Maybe docker is popular enough that it makes sense to have it front-and-center.

[ebr]

Thanks! yeah, we occasionally see questions on where to find the official images, so I think it's helpful to have a one-liner in the main README that "just works" to get started. Agreed that the more extensive docs should stay in the other locations - i tried to keep it that way.