Update analyzers.md - Add analyzer evaluation checklist

What does this MR do?

Adds checklist guidelines for how to evaluate a new tool when writing an analyzer; including minimum fields.

I put this together during evaluation of https://gitlab.com/gitlab-org/gitlab-ee/issues/10680 and thought it a good idea to formalize. It's currently quite minimal but happy to expand and iterate.

What are the relevant issue numbers?

Does this MR meet the acceptance criteria?

• [-] Changelog entry added
• [-] Documentation created/updated for GitLab EE, if necessary
• Documentation created/updated for this project, if necessary
• Documentation reviewed by technical writer or follow-up review issue created
• [-] Tests added for this feature/bug
• [-] Job definition updated, if necessary
  • [-] Job definition example
  • [-] CI Templates (to be removed)
  • [-] Vendored CI Templates (also in CE)
  • [-] Ensure that all of the ENV vars supported are propagated to Docker containers upon docker run in job definitions
• Conforms to the code review guidelines
• Conforms to the Go guidelines
• Security reports checked/validated by reviewer