Mention JdbcClient in package documentation

Closes gh-31017

Author: jhoeller

spring-jdbc/src/main/java/org/springframework/jdbc/core/simple/JdbcClient.java

@@ -37,7 +37,7 @@
 import org.springframework.jdbc.support.rowset.SqlRowSet;
 
 /**
- * A fluent {@link JdbcClient} with common JDBC query and update operations,
+ * A fluent {@code JdbcClient} with common JDBC query and update operations,
  * supporting JDBC-style positional as well as Spring-style named parameters
  * with a convenient unified facade for JDBC PreparedStatement execution.
  *

spring-jdbc/src/main/java/org/springframework/jdbc/core/simple/package-info.java

@@ -1,5 +1,8 @@
 /**
- * Simplification layer for table inserts and stored procedure calls.
+ * Simplification layer for common JDBC interactions.
+ *
+ * <p>{@code JdbcClient} provides a fluent API for JDBC query and update operations,
+ * supporting JDBC-style positional as well as Spring-style named parameters.
  *
  * <p>{@code SimpleJdbcInsert} and {@code SimpleJdbcCall} take advantage of database
  * meta-data provided by the JDBC driver to simplify the application code. Much of the