Update readme.md

Author: dkrnl

readme.md

@@ -4,6 +4,24 @@ Wrapper XMLReader(http://php.net/manual/ru/book.xmlreader.php) class, for simple
 
 **Minimum the memory** usage of other xml libraries(SimpleXML, DOMXML).
 
-Usage example: http://github.com/dkrnl/SimpleXMLReader/blob/master/examples/example1.php
+Usage example 1:
+```php
+$reader = new SimpleXMLReader;
+$reader->open("big.xml");
+$reader->registerCallback("by-node-name", function($reader) {
+    $element = $reader->expandSimpleXml(); // copy of the current node as a SimpleXMLElement object
+    $attributes = $element->attributes(); // read element attributes
+    /* ... */
+});
+$reader->registerCallback("/by/xpath/query", function($reader) {
+    $element = $reader->expandSimpleXml(); // copy of the current node as a SimpleXMLElement object
+    $attributes = $element->attributes(); // read element attributes
+    /* ... */
+});
+$reader->parse();
+$reader->close();
+
+```
+Usage example 2: http://github.com/dkrnl/SimpleXMLReader/blob/master/examples/example1.php
 
 License: Public Domain