Add documentation about variables usage in GitLab CI

1 files changed, 4 insertions, 2 deletions

diff --git a/doc/ci/README.md b/doc/ci/README.md
index 8d1d72c2a2b..7666219acb0 100644
--- a/doc/ci/README.md
+++ b/doc/ci/README.md
@@ -19,7 +19,7 @@ Here's some info we've gathered to get you started.
 The first steps towards your GitLab CI/CD journey.
 
 - [Getting started with GitLab CI/CD](quick_start/README.md): understand how GitLab CI/CD works.
-- GitLab CI/CD configuration file: [`.gitlab-ci.yml`](yaml/README.md) - Learn all about the ins and outs of `.gitlab-ci.yml`.
+- [GitLab CI/CD configuration file: `.gitlab-ci.yml`](yaml/README.md) - Learn all about the ins and outs of `.gitlab-ci.yml`.
 - [Pipelines and jobs](pipelines.md): configure your GitLab CI/CD pipelines to build, test, and deploy your application.
 - Runners: The [GitLab Runner](https://docs.gitlab.com/runner/) is responsible by running the jobs in your CI/CD pipeline. On GitLab.com, Shared Runners are enabled by default, so
 you don't need to set up anything to start to use them with GitLab CI/CD.
@@ -46,7 +46,9 @@ you don't need to set up anything to start to use them with GitLab CI/CD.
 ## Exploring GitLab CI/CD
 
 - [CI/CD Variables](variables/README.md) - Learn how to use variables defined in
-  your `.gitlab-ci.yml` or secured ones defined in your project's settings
+  your `.gitlab-ci.yml` or the ones defined in your project's settings
+  - [Where variables can be used](variables/where_variables_can_be_used.md) - A
+    deeper look on where and how the CI/CD variables can be used
 - **The permissions model** - Learn about the access levels a user can have for
   performing certain CI actions
   - [User permissions](../user/permissions.md#gitlab-ci)