Add links to clarify What's New 4.2.0 items. (#2650)

closes #2621

src/main/docs/guide/whatsNew.adoc

@@ -1,10 +1,12 @@
 === Micronaut Data 4.2
-- Procedure invocations in repositories
+- Procedure invocations in repositories for <<hibernateProcedures, Data JPA>> and <<dbcProcedures, Data JDBC/R2DBC>>
 - Added possibility to have associations (JOINs) in DTOs
 - Support for inserts, updates and deletes with `RETURNING` clause in repositories
-- MongoDB: Support `arrayFilters`
-- Kotlin: New coroutine variations of connection / transaction operations: `io.micronaut.data.connection.kotlin.CoroutineConnectionOperations`, `io.micronaut.transaction.kotlin.CoroutineTransactionOperations`
-- R2DBC: New connection status callback. Corrected cancellation.
+- MongoDB: Support link:https://www.mongodb.com/docs/manual/reference/operator/update/positional-filtered/[`arrayFilters`]
+- Kotlin: New coroutine variations of connection / transaction operations:
+    * `io.micronaut.data.connection.kotlin.CoroutineConnectionOperations`
+    * `io.micronaut.transaction.kotlin.CoroutineTransactionOperations`
+- R2DBC: New link:{api}/io/micronaut/data/connection/reactive/ReactiveConnectionSynchronization.html[connection status callback]. Corrected cancellation.
 
 === Micronaut Data 4.1
 - Support NESTED transaction propagation