fix md

Author: cangelis

README.md

@@ -35,7 +35,9 @@ php-pdf uses [League\Flysystem](https://github.com/thephpleague/flysystem) to sa
     $pdfObject->save(string $filename, League\Flysystem\AdapterInterface $adapter, $overwrite)
 
 `filename`: the name of the file you want to save with
+
 `adapter`: FlySystem Adapter
+
 `overwrite`: If set to `true` and the file exists it will be overwritten, otherwise an Exception will be thrown.
 
 ### Examples