changelog(): updated changelog with info on shared tooltip feature merged via PR…

changelog(): updated changelog with info on shared tooltip feature merged via PR #6274, closes #1578

CHANGELOG.md

 # 4.1-beta (unreleased)
 
-### Bugfixes
-* **API**: HTTP API for deleting org returning incorrect message for a non-existing org [#6679](https://github.com/grafana/grafana/issues/6679)
-* **Dashboard**: Posting empty dashboard result in corrupted dashboard [#5443](https://github.com/grafana/grafana/issues/5443)
-
 ### Enhancements
 * **Postgres**: Add support for Certs for Postgres database [#6655](https://github.com/grafana/grafana/issues/6655)
 * **Victorops**: Add VictorOps Notification Integration [#6411](https://github.com/grafana/grafana/issues/6411)
 * **Singlestat**: New aggregation on singlestat panel [#6740](https://github.com/grafana/grafana/pull/6740)
 * **Cloudwatch**: Make it possible to specify access and secret key on the data source config page [#6697](https://github.com/grafana/grafana/issues/6697)
 * **Table**: Added Hidden Column Style for Table Panel [#5677](https://github.com/grafana/grafana/pull/5677)
+* **Graph**: Shared crosshair option renamed to shared tooltip, shows tooltip on all graphs as you hover over one graph. [#1578](https://github.com/grafana/grafana/pull/1578), [#6274](https://github.com/grafana/grafana/pull/6274)
+
+### Bugfixes
+* **API**: HTTP API for deleting org returning incorrect message for a non-existing org [#6679](https://github.com/grafana/grafana/issues/6679)
+* **Dashboard**: Posting empty dashboard result in corrupted dashboard [#5443](https://github.com/grafana/grafana/issues/5443)
 
 # 4.0.2 (unreleased)