Update doc/observability/metrics.md

Co-authored-by: Jason Madigan <[email protected]>

doc/observability/metrics.md

@@ -30,7 +30,7 @@ these metrics being scraped.
 
 ## Networking metrics
 
-Low level networking metrics like `container_network_receive_bytes_total` are also
+Low-level networking metrics like `container_network_receive_bytes_total` are also
 available from the Kubernetes metrics components.
 HTTP & GRPC traffic metrics with higher level labels are [available from Istio](https://istio.io/latest/docs/reference/config/metrics/).
 One of the main metrics would be `istio_requests_total`, which is a counter incremented for every request handled by an Istio proxy.