Add link between reference and how-to

See gh-7652

Author: snicoll

spring-boot-docs/src/main/asciidoc/spring-boot-features.adoc

@@ -2711,6 +2711,9 @@ Java's `javax.sql.DataSource` interface provides a standard method of working wi
 database connections. Traditionally a DataSource uses a `URL` along with some
 credentials to establish a database connection.
 
+TIP: Check also <<the '`How-to`' section,howto.adoc#howto-configure-a-datasource] for more
+advanced examples, typically to take full control over the configuration of the
+DataSource.
 
 
 [[boot-features-embedded-database-support]]