[Update guide] Variables in scripts and configuration profiles (#34955)

- Add a link to Fleet's built-in variables to make them easier to find.
When search "variables" in the docs/guide, this guide is the first to
come up:


<img width="579" height="515" alt="Screenshot 2025-10-29 at 4 12 39 PM"
src="https://github.com/user-attachments/assets/bc8b2722-2e6c-446f-8cce-9fb4cc4a0ed3"
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Co-authored-by: Mike Thomas <78363703+mike-j-thomas@users.noreply.github.com>

articles/secrets-in-scripts-and-configuration-profiles.md

@@ -6,8 +6,7 @@
 
 In Fleet you can add variables, in [scripts](https://fleetdm.com/guides/scripts) and [configuration profiles](https://fleetdm.com/guides/custom-os-settings). Variables are hidden when the script or configuration profile is viewed in the Fleet UI or API.
 
-Variables can be defined using [Fleet's YAML (GitOps)](https://fleetdm.com/docs/configuration/yaml-files) or via the UI under `Controls` > `Variables`.
-If you are using GitOps, variables aren't removed on GitOps runs. You can delete them on the `Controls` > `Variables` page.
+Configuration profiles can also use any of Fleet's [built-in variables](https://fleetdm.com/docs/configuration/yaml-files#variables).
 
 ## Add variables
 
@@ -45,6 +44,8 @@ When GitOps syncs the configuration, it looks for variables in scripts and profi
 
 On subsequent GitOps syncs, if a variable is used by an updated configuration profile, the profile will be resent to the host device(s).
 
+Variables aren't removed on GitOps runs. To remove a variable, delete it on the `Controls` > `Variables` page.
+
 > Profiles with variables are not entirely validated during a GitOps dry run because the required variables may not exist or may be incorrect in the database. As a result, these profiles have a higher chance of failing during a non-dry run. Test them by uploading to a small team first.
 
 ## Using the secret on a configuration profile