update xdoc files with code examples for all checks at http://checkstyle.sourceforge.net/config_naming.html
sources are at https://github.com/checkstyle/checkstyle/blob/master/src/xdocs/config_naming.xml

Good example is http://checkstyle.sourceforge.net/config_annotation.html#AnnotationLocation
sources are at https://github.com/checkstyle/checkstyle/blob/master/src/xdocs/config_annotation.xml