docs: fix links

README.md

@@ -187,10 +187,13 @@ tokio::spawn(do_work());
 
 If you also enable the `metrics-rs-integration` feature, you can use [metrics.rs] exporters to export metrics outside of your process. `metrics.rs` supports a variety of exporters, including [Prometheus].
 
-The exported metrics by default will be exported with their name, preceded by `tokio_`. For example, `tokio_workers_count` for the [`workers_count`] metric. This can be customized by using the `with_metrics_tranformer` function.
+The exported metrics by default will be exported with their name, preceded by `tokio_`. For example, `tokio_workers_count` for the [`workers_count`] metric. This can be customized by using the [`with_metrics_tranformer`] function.
 
 If you want to use [Prometheus], you could have this `Cargo.toml`:
 
+[Prometheus]: https://prometheus.io
+[`with_metrics_tranformer`]: https://docs.rs/tokio-metrics/0.4.*/tokio_metrics/struct.RuntimeMetricsReporterBuilder.html#method.with_metrics_transformer
+
 ```toml
 [dependencies]
 tokio-metrics = { version = "0.4.1", features = ["metrics-rs-integration"] }

src/lib.rs

@@ -110,16 +110,17 @@ If the `metrics-rs-integration` feature is additionally enabled, this crate allo
 publishing runtime metrics externally via [metrics-rs](metrics) exporters.
 
 For example, you can use [metrics_exporter_prometheus] to make metrics visible
-to Prometheus. You can see the [metrics_exporter_prometheus] and [metrics-rs](metrics)
+to [Prometheus]. You can see the [metrics_exporter_prometheus] and [metrics-rs](metrics)
 docs for guidance on configuring exporters.
 
 The published metrics are the same as the fields of [RuntimeMetrics], but with
 a "tokio_" prefix added, for example `tokio_workers_count`.
 
 [metrics_exporter_prometheus]: https://docs.rs/metrics_exporter_prometheus
 [RuntimeMetrics]: crate::RuntimeMetrics
+[Prometheus]: https://prometheus.io
 
-This example exports Prometheus metrics by listening on a local Unix socket
+This example exports [Prometheus] metrics by listening on a local Unix socket
 called `prometheus.sock`, which you can access for debugging by
 `curl --unix-socket prometheus.sock localhost`.