docs: add clarification for queue usage scenarios (#53)

* add clarification for queue usage scenarios

* fix wording

Author: michalsn

README.md

@@ -11,6 +11,9 @@ Queues for the CodeIgniter 4 framework.
 ![CodeIgniter](https://img.shields.io/badge/CodeIgniter-%5E4.3-blue)
 ![License](https://img.shields.io/badge/License-MIT-blue)
 
+> [!NOTE]
+> A queue system is typically used to handle resource-intensive or time-consuming tasks (e.g., image processing, sending emails) that are to be run in the background. It can also be a way to postpone certain activities that are to be executed automatically later.
+
 ## Installation
 
     composer require codeigniter4/queue

docs/index.md

@@ -2,7 +2,11 @@
 
 A library that helps you handle Queues in the CodeIgniter 4 framework.
 
-Add job to the queue.
+!!! info "What are queues used for?"
+
+    A queue system is typically used to handle resource-intensive or time-consuming tasks (e.g., image processing, sending emails) that are to be run in the background. It can also be a way to postpone certain activities that are to be executed automatically later.
+
+Add a job to the queue.
 
 ```php
 service('queue')->push('queueName', 'jobName', ['array' => 'parameters']);