Explain how to configure logback

[stefan-jung]

Description

The topic logging explains how to configure FOP logging with logback. It would be great to find an example here of how to add a custom logback.xml file to the classpath.

To enable debug logging, modify the config/logback.xml file or add your own logback.xml to the classpath with a higher priority to override the default settings. For more information, see the Logback configuration documentation.