Fix insights illustration

What does this MR do and why?

Replace getting_started with empty-dashboard-md

Screenshots or screen recordings

Before	After

How to set up and validate locally

1. Create a new project
2. Choose a tab from the nav menu Analyze > Insights
3. See illustration. Maybe you need to reload the page a few times

MR acceptance checklist

This checklist encourages us to confirm any changes have been analyzed to reduce risks in quality, performance, reliability, security, and maintainability.

• I have evaluated the MR acceptance checklist for this MR.

#430244 (closed)