ci(danger): reintroduce technical writers in docs reviews

This MR reintroduces Technical Writers in the reviewers roulette when documentation changes are detected in the doc/ directory.

As per GitLab UI's requirements, when a documentation review is required, we recommend only an initial review by a technical writer. The maintainer review should still be done by a frontend maintainer.

Any other change will be require a frontend review.

Here's an MR that contains a documentation change to demonstrate the expected behavior: !1240 (closed)

Closes #632 (closed)