Add changelog for version to 6.9.1.

CHANGELOG

@@ -10,6 +10,10 @@ v 7.0.0
   - Drag and drop upload of image in every markdown-area (Earle Randolph Bunao and Neil Francis Calabroso)
   - Refactor the markdown relative links processing
 
+v 6.9.1
+  - Fix scroll to highlighted line
+  - Fix the pagination on load for commits page
+
 v 6.9.0
   - Store Rails cache data in the Redis `cache:gitlab` namespace
   - Adjust MySQL limits for existing installations