Add changelog entry

CHANGELOG-EE

@@ -3,6 +3,7 @@ v 8.4.0 (unreleased)
   - Fix "Commit was rejected by git hook", when max_file_size was set null in project's Git hooks
   - Fix "Approvals are not reset after a new push is made if the request is coming from a fork"
   - Fix "User is not automatically removed from suggested approvers list if user is deleted"
+  - Add option to enforce a semi-linear history by only allowing merge requests to be merged that have been rebased.
 
 v 8.3.2
   - No EE-specific changes
@@ -14,9 +15,9 @@ v 8.3.0
   - License information can now be retrieved via the API
   - Show Kerberos clone url when Kerberos enabled and url different than HTTP url (Borja Aparicio)
   - Fix bug with negative approvals required
-  - Add group contribution analytics page 
+  - Add group contribution analytics page
   - Add GitLab Pages
-  - Add group contribution statistics page 
+  - Add group contribution statistics page
   - Automatically import Kerberos identities from Active Directory when Kerberos is enabled (Alex Lossent)
   - Canonicalization of Kerberos identities to always include realm (Alex Lossent)
 
@@ -60,7 +61,7 @@ v 8.1.1
 v 8.1.0
   - Add documentation for "Share project with group" API call
   - Added an issues template (Hannes Rosenögger)
-  - Add documentation for "Share project with group" API call 
+  - Add documentation for "Share project with group" API call
   - Ability to disable 'Share with Group' feature (via UI and API)
 
 v 8.0.6