[Docs] Update kanvas/getting-started to reference narrative characters

[leecalcote]

Overview

Update kanvas/getting-started so Jordan Reyes opens the microservices-baseline design and Five reviews it.

Tasks

• Introduce Jordan as the user opening Kanvas Designer with microservices-baseline
• Add Five as the reviewer/collaborator
• Update screenshots to use narrative accounts
• Link to /cloud/about for full cast context

Reference

• Narrative: /cloud/about
• Difficulty: Medium