Add --dev option to composer require (#95)

* update readme.md

* formating

README.md

@@ -14,9 +14,12 @@ Configuration paths have changed in Laravel 5.7, in order for this package to fu
 ## Install the package
 
 In your project:
-```composer require martinlindhe/laravel-vue-i18n-generator```
+```composer require martinlindhe/laravel-vue-i18n-generator --dev```
 
-In ```config/app.php``` providers:
+### For Laravel 5.4 and below:
+For older versions of the framework:
+
+Register the service provider in ```config/app.php```
 
 ```php
 MartinLindhe\VueInternationalizationGenerator\GeneratorProvider::class,