add new method in readme

FreedomKnight · FreedomKnight · commit ab949656f670 · 2018-06-26T10:31:28.000+08:00
diff --git a/README.md b/README.md
@@ -84,6 +84,14 @@ $post->recategorize(1, "news");
 
 ```
 
+### hasCategories
+
+You can find model which has specify categories
+
+```php
+Post::hasCategories('News', 1)->get();
+```
+
 
 ## Change log
 
