docs(changelog): updated changelog with new ux improvements

CHANGELOG.md

@@ -17,6 +17,8 @@
 * **Graph Panel**: Now supports flexible lower/upper bounds on Y-Max and Y-Min, PR [#5720](https://github.com/grafana/grafana/pull/5720)
 * **Background Tasks**: Now support automatic purging of old snapshots, closes [#4087](https://github.com/grafana/grafana/issues/4087)
 * **Background Tasks**: Now support automatic purging of old rendered images, closes [#2172](https://github.com/grafana/grafana/issues/2172)
+* **Dashboard**: After inactivity hide nav/row actions, fade to nice clean view, can be toggled with `d v`, also added kiosk mode, toggled via `d k` [#6476](https://github.com/grafana/grafana/issues/6476)
+* **Dashboard**: Improved dashboard row menu & add panel UX [#6442](https://github.com/grafana/grafana/issues/6442)
 
 ### Breaking changes
 * **SystemD**: Change systemd description, closes [#5971](https://github.com/grafana/grafana/pull/5971)