Add missing documentation

See gh-12129

spring-boot-project/spring-boot-docs/src/main/asciidoc/production-ready-features.adoc

@@ -1563,13 +1563,15 @@ is required. A `CacheMetricsRegistrar` bean is made available to make that proce
 
 [[production-ready-metrics-jdbc]]
 ==== DataSource Metrics
-Auto-configuration enables the instrumentation of all available ``DataSource`` objects
-with a metric named `jdbc`. Data source instrumentation results in gauges representing the
+Auto-configuration enables the instrumentation of all available DataSource` objects with a
+metric named `jdbc`. Data source instrumentation results in gauges representing the
 currently active, maximum allowed, and minimum allowed connections in the pool. Each of
 these gauges has a name that is prefixed by `jdbc`.
 
 Metrics are also tagged by the name of the `DataSource` computed based on the bean name.
 
+Also, Hikari-specific metrics are exposed with a `hikaricp` prefix. Each metric is tagged
+by the name of the Pool (can be controlled with `spring.datasource.name`).
 
 
 [[production-ready-metrics-rabbitmq]]