Adds docker and docker-compose to the playwright image.
Can be used as a runner in GitLab like this:
docker exec -it gitlab-runner \
gitlab-runner \
register -n \
--name "playwright" \
--tag-list "playwright" \
--docker-image "jdalrymple/playwright-with-docker-compose:latest" \
--docker-privileged \
--docker-volumes "/var/run/docker.sock:/var/run/docker.sock" \
--docker-volumes "/cache"