Update Grafana demo dashboard link (#302)

Signed-off-by: Nitish Tiwari <[email protected]>

Author: nitisht

README.md

@@ -24,7 +24,7 @@ Parseable is written in Rust and uses Apache Arrow and Parquet as underlying dat
 Parseable consumes up to **_~80% lower memory_** and **_~50% lower CPU_** than Elastic for similar ingestion throughput.
 
 - [Parseable UI Demo (Credentials: admin,admin) ↗︎](https://www.parseable.io/docs/)
-- [Grafana Dashboard Demo ↗︎](http://demo.parseable.io:3000/d/ojonXSp4zas/parseable-demo-data-test?orgId=1&refresh=30m)
+- [Grafana Dashboard Demo ↗︎](http://demo.parseable.io:3000/dashboards)
 
 ## :rocket: Features