Update documentation around running evaluations locally

What does this merge request do and why?

Update documentation around running evaluations locally

• Separate chat and code suggestions instructions
  • note that the chat evaluation instructions are outdated and will be update in !60 (merged)
• Add instructions for analyzing or comparing the results of code suggestions

How to set up and validate locally

N/A

Merge request checklist

• Tests added for new functionality. If not, please raise an issue to follow up.
• Documentation added/updated, if needed.