Merge branch 'dz-update-changelog' into 'master'

Add UI changes in 8.8 to changelog

For !3824 and !3980

[ci skip]

See merge request !4140

CHANGELOG

@@ -49,6 +49,8 @@ v 8.8.0 (unreleased)
   - Total method execution timings are no longer tracked
   - Allow Admins to remove the Login with buttons for OAuth services and still be able to import !4034. (Andrei Gliga)
   - Add API endpoints for un/subscribing from/to a label. !4051 (Ahmad Sherif)
+  - Hide left sidebar on phone screens to give more space for content
+  - Redesign navigation for profile and group pages
 
 v 8.7.5
   - Fix relative links in wiki pages. !4050