chore(docs): Updated API Reference (#6041)

Automated changes by [create-pull-request](https://github.com/peter-evans/create-pull-request) GitHub action

Co-authored-by: Oli Juhl <59018053+olivermrbl@users.noreply.github.com>
Co-authored-by: Shahed Nasser <27354907+shahednasser@users.noreply.github.com>

www/apps/api-reference/specs/admin/components/schemas/Order.yaml

@@ -339,3 +339,11 @@ properties:
       description: Learn about the metadata attribute, and how to delete and update it.
       url: >-
         https://docs.medusajs.com/development/entities/overview#metadata-attribute
+  sales_channels:
+    description: The associated sales channels.
+    type: array
+    nullable: true
+    x-expandable: sales_channels
+    x-featureFlag: medusa_v2
+    items:
+      $ref: ./SalesChannel.yaml