Update readme.md

Author: youchenlee

readme.md

@@ -8,7 +8,7 @@ Laravel File API is good way to handle files with Laravel Storage.
 
 1. Install File API
 
-    composer require unisharp/laravel-fileapi
+    `composer require unisharp/laravel-fileapi`
 
 1. Set service provider in `config/app.php`
 
@@ -18,7 +18,7 @@ Laravel File API is good way to handle files with Laravel Storage.
 
 1. publish config file
 
-    php artisan vendor:publish --tag=fileapi_config
+    `php artisan vendor:publish --tag=fileapi_config`
 
 ### Config