Update doc/observability/metrics.md

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

doc/observability/metrics.md

@@ -21,7 +21,7 @@ and how to join the metrics from different sources together in a meaningful way.
 Resource metrics, like CPU, memory and disk usage, primarily come from the Kubernetes
 metrics components. These include `container_cpu_usage_seconds_total`, `container_memory_working_set_bytes`
 and `kubelet_volume_stats_used_bytes`. A [stable list of metrics](https://github.com/kubernetes/kubernetes/blob/master/test/instrumentation/testdata/stable-metrics-list.yaml) is maintained in
-the kubernetes repository. These low level metrics typically have a set of
+the kubernetes repository. These low-level metrics typically have a set of
 [recording rules](https://prometheus.io/docs/practices/rules/#aggregation) that
 aggregate values by labels and time ranges.
 For example, `node_namespace_pod_container:container_cpu_usage_seconds_total:sum_irate` or `namespace_workload_pod:kube_pod_owner:relabel`.