update readme

Author: streamtw

readme.md

@@ -8,15 +8,21 @@ Laravel File API is good way to handle files with Laravel Storage.
 
 1. Install File API
 
-    ```composer require unisharp/laravel-fileapi```
+    ```php
+        composer require unisharp/laravel-fileapi
+    ```
 
 1. Set service provider in `config/app.php`
 
-    ````Unisharp\FileApi\FileApiServiceProvider::class,```
+    ```php
+        Unisharp\FileApi\FileApiServiceProvider::class,
+    ```
 
 1. publish config file
 
-    ```php artisan vendor:publish --tag=fileapi_config```
+    ```php
+        php artisan vendor:publish --tag=fileapi_config
+    ```
 
 1. fill the path in config/fileapi.php, it will generate routes for your files.