Added documentation for chunk method of AR

Author: Samuel Akopyan

docs/js/highlight/lang-php.js

@@ -291,6 +291,7 @@
         "setGuarded",
         "CTime",
         "getMicrotime",
+        "chunk",
     ];
 
 	var BUILTINS = {};

docs/pages/models.html

@@ -11,7 +11,7 @@ <h1>Development - Models</h1>
             <li><a href="#creating_record">Creating Record</a></li>
             <li><a href="#updating_record">Updating Record</a></li>
             <li><a href="#deleting_record">Deleting Record</a></li>
-            <li><a href="#reading_record">Reading Record</a></li>
+            <li><a href="#reading_records">Reading Records</a></li>
             <li><a href="#additional_methods">Additional Methods</a></li>
         </ul>            
     </li>
@@ -415,8 +415,8 @@ <h4>Deleting Record</h4>
 <br>
 
 
-<a name="reading_record"></a>
-<h4>Reading Record</h4>
+<a name="reading_records"></a>
+<h4>Reading Records</h4>
 To read data from a database table, we can use one of the find methods as follows.
 
 <pre name="dlhl" class="php">
@@ -433,6 +433,20 @@ <h4>Reading Record</h4>
 // Finds all rows satisfying the specified conditions with %LIKE%
 $news = News:model()->findAll(CConfig::get('db.prefix').$this->_tableTranslation.'.news_text LIKE :keywords', array(':keywords'=>'%'.$keywords.'%'));
 </pre>
+
+Reading records with chunks. The chunk method breaks the record set into small parts of a given size
+<pre name="dlhl" class="php">
+$posts = [];
+// 1st parameter - conditions
+// 2nd parameter - condition parameters
+// 3rd parameter - chunk size
+// 4th parameter - callback function
+Posts::model()->chunk($conditions, [], 10, function ($records) use(&$posts){
+    foreach ($records as $key => $record) {
+        $posts[] = $record;
+    }
+});
+</pre>
 <br>