Inform about the EE features.

doc/integration/README.md

@@ -7,3 +7,5 @@ See the documentation below for details on how to configure these services.
 + [LDAP](ldap.md) Set up sign in via LDAP
 + [OmniAuth](omniauth.md) Sign in via Twitter, GitHub, and Google via OAuth.
 + [Slack](slack.md) Integrate with the Slack chat service
+
+Jenkins support is [available in GitLab EE](http://doc.gitlab.com/ee/integration/jenkins.html).

doc/integration/external-issue-tracker.md

@@ -7,3 +7,5 @@ GitLab has a great issue tracker but you can also use an external issue tracker
 ![jira screenshot](jira-integration-points.png)
 You can configure the integration in the gitlab.yml configuration file.
+
+Support to add your commits to the Jira ticket automatically is [available in GitLab EE](http://doc.gitlab.com/ee/integration/jira.html).