docs(changelog): add info about templated timeshift

CHANGELOG.md

@@ -22,6 +22,7 @@
 * **Admin**: Admin can now have global overview of Grafana setup, closes [#3812](https://github.com/grafana/grafana/issues/3812)
 * **graph**: Right side legend height is now fixed at row height, closes [#1277](https://github.com/grafana/grafana/issues/1277)
 * **Table**: All content in table panel is now html escaped, closes [#3673](https://github.com/grafana/grafana/issues/3673)
+* **graph**: Template variables can now be used in TimeShift and TimeFrom, closes[#1960](https://github.com/grafana/grafana/issues/1960)
 
 ### Bug fixes
 * **Playlist**: Fix for memory leak when running a playlist, closes [#3794](https://github.com/grafana/grafana/pull/3794)