Updates re: cockroachdb/docs#7442

Author: Eric Harmeling

roach-data-jdbc/src/main/java/io/roach/data/jdbc/AccountRepository.java

@@ -14,8 +14,6 @@
 /**
  * The main account repository, notice there's no implementation needed since its auto-proxied by
  * spring-data.
- * <p>
- * Should have extended PagingAndSortingRepository in normal cases.
  */
 @Repository
 @Transactional(propagation = MANDATORY)

roach-data-jdbc/src/main/java/io/roach/data/jdbc/PagedAccountRepositoryImpl.java

@@ -10,7 +10,7 @@
 import static org.springframework.transaction.annotation.Propagation.MANDATORY;
 
 @Repository
-// @Transactional is not needed but here for clarity since we want repos to always be called from a tx context
+// @Transactional annotation here to emphasise that repositories should always be called within an existing transaction context
 @Transactional(propagation = MANDATORY)
 public class PagedAccountRepositoryImpl implements PagedAccountRepository {
     @Autowired