add php to markdown

Author: dhcmega

README.md

@@ -285,7 +285,7 @@ $post = Post::meta()
 
 When you need to retrive multiple results from your model, you can eager load `metas`
 
-```
+```php
 $post = Post::with(['metas'])->get();
 ```
 
@@ -294,7 +294,7 @@ $post = Post::with(['metas'])->get();
 When you convert a model to an array (or json) and you don't need all meta fields, you can create a model's property to prevent metas from being added to the resulting array.
 You can also use it on eloquent relations.
 
-```
+```php
 /* Post model */
 public $hideMeta = true; // Do not add metas to array
 ```