DATAJDBC-483 - Fixes small documentation issues.

Add anchor to section on JdbcValue in reference documentation.

Original pull request: #189.

Author: taeyeonkim

src/main/asciidoc/jdbc.adoc

@@ -474,7 +474,7 @@ For example, the following listener gets invoked before an aggregate gets saved:
 [source,java]
 ----
 @Bean
-public ApplicationListener<BeforeSave> timeStampingSaveTime() {
+public ApplicationListener<BeforeSaveEvent> timeStampingSaveTime() {
 
 	return event -> {