fix readme

Piotr Krajewski · Piotr Krajewski · commit 109059ba137f · 2017-11-23T09:42:59.000+01:00
diff --git a/README.md b/README.md
@@ -105,7 +105,7 @@ usage:
 
 to delete nested row you should pass `_destroy` attribute:
 
-```
+``` php
 \App\Post::findOrFail(1)->update([
     'title' => 'Better text',
 
