Merge branch 'docs/ssot_admin_area_license' into 'master'

Edit License details to comply with SSOT guidelines

See merge request gitlab-org/gitlab-ce!28529

doc/user/admin_area/license.md

+---
+type: howto
+---
+
 # Activate all GitLab Enterprise Edition functionality with a license **[STARTER ONLY]**
 
 To activate all GitLab Enterprise Edition (EE) functionality, you need to upload
@@ -108,3 +112,15 @@ but only the latest license will be used as the active license.
 
 [free trial]: https://about.gitlab.com/free-trial/
 [pricing]: https://about.gitlab.com/pricing/
+
+<!-- ## Troubleshooting
+
+Include any troubleshooting steps that you can foresee. If you know beforehand what issues
+one might have when setting this up, or when something is changed, or on upgrading, it's
+important to describe those, too. Think of things that may go wrong and include them here.
+This is important to minimize requests for support, and to avoid doc comments with
+questions that you know someone might ask.
+
+Each scenario can be a third-level heading, e.g. `### Getting error message X`.
+If you have none to add when creating a doc, leave this section in place
+but commented out to help encourage others to add to it in the future. -->
\ No newline at end of file