The Linux Server getting started guide shows the wrong screenshot
when referring to the Teleport welcome screen. This change uses
a screenshot of the view an unauthenticated user would see when
first visiting the Web UI.
* DigitalOcean 1-click Droplet and Kubernetes getting started guides
Co-authored-by: Paul Gottschling <paul.gottschling@goteleport.com>
Co-authored-by: Ben Arent <ben@goteleport.com>