add logging to spring controller code example

Example 1: spring security logging

logging:
  level:
    org:
      springframework:
        security: DEBUG

Example 2: professional logging in spring boot

                                              %black(%d{ISO8601}) %highlight(%-5level) [%blue(%t)] %yellow(%C{1.}): %msg%n%throwable                                     ${LOGS}/spring-boot-logger.log                    %d %p %C{1.} [%t] %m%n                                         ${LOGS}/archived/spring-boot-logger-%d{yyyy-MM-dd}.%i.log                                        10MB