chore: add documentation review apps to project

Description

While working on some documentation for this project, I noticed you can't preview documentation changes.

This MR adds review apps for documentation to the project and we make a documentation change so we can test the functionality:

• Before: https://docs.gitlab.com/cli/runner/jobs/
• After: https://docs.gitlab.com/upstream-review-mr-cli-3034/cli/runner/jobs/