Document role of @relotnek in security operations

[relotnek]

Added comments explaining the role of @relotnek in the Filecoin Foundation.

Summary

Why do you need this?

What else do we need to know?

DRI: myself

Reviewer's Checklist

• It is clear where the request is coming from (if unsure, ask)
• All the automated checks passed
• The YAML changes reflect the summary of the request
• The Terraform plan posted as a comment reflects the summary of the request

[github-actions]

The following access changes will be introduced as a result of applying the plan:

Access Changes

User relotnek:
  - will have the role in the organization change from member to admin