Don't run in detached mode
Created by: nicksnyder
The two other places we document this command (https://about.sourcegraph.com/get-started/self-hosted, https://docs.sourcegraph.com/admin/deploy/docker-single-container), it does not run in detached mode so it seems like we shouldn't recommend running detached here.
I think running in detached mode the first time by default isn't great UX because then you don't see when it is ready.
Test plan
Previewed markdown doc in GitHub