Runner Ref Arch: Report baseline performance for runner architecture in GitLab Reference Architecture documentation

Problem

Communicate starting point of Runner Reference Architecture recommendations based upon new load testing against Staging-Ref with new GPT tests and custom runner deployment.

Tasks

• Create documentation to be added to GitLab Reference Architecture documentation
• Consider creating a blog post if that makes sense and publish on GitLab.com blogs
• Invite contributors to contribute requirements for their specific scenarios