Add readme file

README.md

+# Queue Order
+
+## Introduction
+
+This is the module that provide functionality of sorting
+queue workers definitions. That causes an effect on queue execution order
+during cron run.
+
+## API
+
+No API.
+
+## Config
+
+All weight values of queue workers stored in `order` property
+of `queue_order.settings` config object. It contains key - value array,
+where key is the id of queue worker, value - the weight value.
+  
+```yaml
+# Example of `queue_order.settings` config object:
+order:
+  queue_worker_1: 0
+  queue_worker_2: -1
+  queue_worker_3: 1
+  queue_worker_4: 2
+``` 
+## UI
+
+This module provide functionality without any admin UI.
+It should be useful on production.
+Use [Queue Order UI](https://www.drupal.org/project/queue_order_ui)
+for development process.