Using inline links for require QA tests part of definition of done per review feedback

What does this MR do?

Updates definition of done to use inline links for require QA tests per review feedback here: https://gitlab.com/gitlab-org/gitlab-ce/merge_requests/22655#note_113956706

Related issues

https://gitlab.com/gitlab-org/quality/team-tasks/issues/67

Author's checklist

• Apply the correct labels and milestone
• Crosslink the document from the higher-level index
• Crosslink the document from other subject-related docs
• Feature moving tiers? Make sure the change is also reflected in features.yml
• Correctly apply the product badges and tiers
• 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