add dump example

example.php

@@ -9,3 +9,7 @@ require_once 'Logger.php';
 $logger = Logger::get_logger('./logs', 'my-log');
 $logger->log("normal log message");
 $logger->log("log with addtional arguments: %s, %s", "msg1", "msg2");
+
+/* Dump */
+$data = array(1,2,3);
+$logger->dump($data, "data"); // or just: $logger->dump($data);