spellcheck fixes (#4724)

polkadot/runtime/metrics/src/with_runtime_metrics.rs

@@ -31,7 +31,7 @@ use primitives::v1::{
 use sp_std::prelude::*;
 
 /// Holds a set of counters that have different values for their labels,
-/// like Prometheus CounterVec.
+/// like Prometheus `CounterVec`.
 pub struct CounterVec {
 	name: &'static str,
 }
@@ -87,7 +87,7 @@ impl CounterVec {
 		CounterVec { name: definition.name }
 	}
 
-	/// Returns a LabeledMetric instance that provides an interface for incrementing
+	/// Returns a `LabeledMetric` instance that provides an interface for incrementing
 	/// the metric.
 	pub fn with_label_values(&self, label_values: &[&'static str]) -> LabeledMetric {
 		LabeledMetric { name: self.name, label_values: label_values.into() }

polkadot/runtime/metrics/src/without_runtime_metrics.rs

@@ -20,9 +20,9 @@
 
 use primitives::v1::metric_definitions::{CounterDefinition, CounterVecDefinition};
 
-/// A dummy Counter.
+/// A dummy `Counter`.
 pub struct Counter;
-/// A dummy CounterVec.
+/// A dummy `CounterVec`.
 pub struct CounterVec;
 
 /// Dummy implementation.