DEVDOCS-5706: [update] Orders V2, update order_source definition (#26)

# [DEVDOCS-5706]

## What changed?
* update the `order_source` definition

## Release notes draft
* We've updated the definition of the order_source property in the Orders V2 API.

## Anything else?
* See Slack conversation: https://bigcommerce.slack.com/archives/C96P5T3J4/p1704292037915419

ping {names}


[DEVDOCS-5706]:
https://bigcommercecloud.atlassian.net/browse/DEVDOCS-5706?atlOrigin=eyJpIjoiNWRkNTljNzYxNjVmNDY3MDlhMDU5Y2ZhYzA5YTRkZjUiLCJwIjoiZ2l0aHViLWNvbS1KU1cifQ

reference/orders.v2.oas2.yml

@@ -4080,8 +4080,14 @@ components:
           example: false
           type: boolean
         order_source:
-          description: Orders submitted from the storeʼs website will include a `www` value. Orders submitted with the Checkout API will be set to `checkout_api`.
-          example: www, iPhone, Android, mobile, manual
+          description: |-
+            The `order_source` is set upon order creation and reflects the origin of the order. It will indicate whether the order was created by one of the following:
+            * storefront 
+            * control panel
+            * manual order
+            * /v2/orders API
+            * Checkout API
+            * or by an integration with an external platform such as Facebook by Meta or Amazon.
           type: string
         consignments:
           $ref: '#/components/schemas/orderConsignments_Resource'