docs(gitlab-ci): added a missing link

Author: jan-molak

src/docs/handbook/integration/gitlab-ci.mdx

@@ -10,7 +10,7 @@ Serenity/JS offers excellent support for [GitLab CI](https://docs.gitlab.com/top
 you can run your acceptance tests in CI, generate rich Serenity BDD reports,
 and publish both living documentation and JUnit-style test results.
 
-In this guide, you'll learn how to configure your GitLab CI pipeline to use the official Serenity/JS Docker image
+In this guide, you'll learn how to configure your GitLab CI pipeline to use the official [Serenity/JS Docker image](/handbook/integration/docker/)
 and ensure a stable environment for running your Serenity/JS test scenarios.
 
 ## Before you start