changelog: adds note about closing 5765

CHANGELOG.md

@@ -16,6 +16,7 @@
 * **Jaeger**: Add support for open tracing using jaeger in Grafana. [#9213](https://github.com/grafana/grafana/pull/9213)
 * **Unit types**: New date & time unit types added, useful in singlestat to show dates & times. [#3678](https://github.com/grafana/grafana/issues/3678), [#6710](https://github.com/grafana/grafana/issues/6710), [#2764](https://github.com/grafana/grafana/issues/6710)
 * **CLI**: Make it possible to install plugins from any url [#5873](https://github.com/grafana/grafana/issues/5873)
+* **Prometheus**: Add support for instant queries [#5765](https://github.com/grafana/grafana/issues/5765), thx [@mtanda](https://github.com/mtanda)
 
 ## Minor
 * **SMTP**: Make it possible to set specific EHLO for smtp client. [#9319](https://github.com/grafana/grafana/issues/9319)