Edit external issue tracker page for style

doc/integration/external-issue-tracker.md

@@ -6,27 +6,26 @@ info: To determine the technical writer assigned to the Stage/Group associated w
 
 # External issue tracker **(FREE)**
 
-GitLab has a great [issue tracker](../user/project/issues/index.md) but you can also use an external
-one. External issue trackers are configurable per GitLab project.
+GitLab has an [issue tracker](../user/project/issues/index.md), but you can
+configure an external issue tracker per GitLab project.
 
-Once configured, you can reference external issues using the format `CODE-123`, where:
+After you configure the external tracker, you can reference external issues
+in GitLab merge requests, commits, and comments
+using the format `CODE-123`, where:
 
 - `CODE` is a unique code for the tracker.
 - `123` is the issue number in the tracker.
 
-These references in GitLab merge requests, commits, or comments are automatically converted to links to the issues.
+The references are automatically converted to links to the issues.
 
 You can keep the GitLab issue tracker enabled in parallel or disable it. When enabled, the **Issues** link in the
 GitLab menu always opens the internal issue tracker. When disabled, the link is not visible in the menu.
 
-## Configuration
+## Configure an external issue tracker
 
-The configuration is done via a project's **Settings > Integrations**.
+To enable an external issue tracker, you must configure the appropriate [integration](../user/project/integrations/index.md).
 
-### Integration
-
-To enable an external issue tracker you must configure the appropriate **Integration**.
-Visit the links below for details:
+The following external issue tracker integrations are available:
 
 - [Bugzilla](../user/project/integrations/bugzilla.md)
 - [Custom Issue Tracker](../user/project/integrations/custom_issue_tracker.md)
@@ -34,3 +33,4 @@ Visit the links below for details:
 - [Jira](../integration/jira/index.md)
 - [Redmine](../user/project/integrations/redmine.md)
 - [YouTrack](../user/project/integrations/youtrack.md)
+- [ZenTao](../user/project/integrations/zentao.md)

doc/user/project/integrations/custom_issue_tracker.md

@@ -8,7 +8,7 @@ info: To determine the technical writer assigned to the Stage/Group associated w
 
 You can integrate an [external issue tracker](../../../integration/external-issue-tracker.md)
 with GitLab. If your preferred issue tracker is not listed in the
-[integrations list](../../../integration/external-issue-tracker.md#integration),
+[integrations list](../../../integration/external-issue-tracker.md#configure-an-external-issue-tracker),
 you can enable a custom issue tracker.
 
 After you enable the custom issue tracker, a link to the issue tracker displays