Dangerbot: mention tech writers based on DevOps stage

What does this MR do?

List tech writers and the categories they are assigned to in dangerbot.

Related issues

https://gitlab.com/gitlab-org/gitlab-ce/issues/49551

Author's checklist

• Apply the correct labels and milestone
• Port the MR to EE (or backport from CE): always recommended, required when the ee-compat-check job fails

Review checklist

• Your team's review (required)
• PM's review (recommended, but not a blocker)
• Technical writer's review (required)
• Merge the EE-MR first, CE-MR afterwards