Add AiGateway Log Locations to Docs

What does this MR do and why?

Adds a brief section for the AiGateway tests outlining the various logs available to aid in troubleshooting failures.

MR acceptance checklist

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

• Commits include Changelog: trailer
• I have evaluated the MR acceptance checklist for this MR.