Update installation.md add explanations for the queue to work correctly

installation.md

@@ -19,6 +19,7 @@ Here's the thing. In the .env, you should pay attention to some of the things be
 -   APP_ENV = You must set this to production so the attendance system will use a server time. But you can set this to local or development so the attendance system will use an inputted time from the request
 -   XENDIT_SECRET_KEY= Copy your xendit api key. This will be use in the rest API
 -   XENDIT_CALLBACK_TOKEN= Copy your xendit callback token. This will be use in the rest API
+-   QUEUE_CONNECTION= databse, change queue_connection to database so that the queue can work correctly
 
 After you setup the database, run the migration and seeder
 
@@ -30,6 +31,7 @@ php artisan db:seed
 Run the server and it was ready to use
 
 ```sh
+php artisan queue:work
 php artisan serve
 ```