Merge pull request #878 from iRevive/docs/metrics

docs: add Grafana dashboard link

Author: iRevive

docs/instrumentation/grafana_dashboard.png

@@ -287,6 +287,13 @@ object Main extends IOApp.Simple {
 
 @:@
 
+## Grafana dashboard
+
+You can use a Grafana [dashboard][grafana-dashboard] to visualize collected metrics.
+
+@:image(grafana_dashboard.png) {
+  alt = Grafana Dashboard
+}
 
 ## Customization
 
@@ -571,3 +578,5 @@ val config: IORuntimeMetrics.Config = {
 
 IORuntimeMetrics.register[IO](runtime.metrics, config)
 ```
+
+[grafana-dashboard]: https://grafana.com/grafana/dashboards/21487-cats-effect-runtime-metrics/

docs/instrumentation/metrics-cats-effect-io-runtime.md

@@ -56,7 +56,7 @@ import org.typelevel.otel4s.trace.Tracer
 object Main extends IOApp.Simple {
   def program(tracer: Tracer[IO]): IO[Unit] =
     tracer.span("test").use { span => // start 'test' span using otel4s
-      println(s"jctx: ${JSpan.current().getSpanContext}") // get a span from a ThreadLocal var
+      println(s"jctx: ${JSpan.current().getSpanContext}") // get a span from a ThreadLocal
       IO.println(s"otel4s: ${span.context}")
     }