chore(docs): Updated API Reference (v2) (#8609)

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

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

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

@@ -5,6 +5,7 @@ required:
   - id
   - name
   - fulfillment_set_id
+  - fulfillment_set
   - geo_zones
   - shipping_options
   - created_at
@@ -23,6 +24,8 @@ properties:
     type: string
     title: fulfillment_set_id
     description: The service zone's fulfillment set id.
+  fulfillment_set:
+    type: object
   geo_zones:
     type: array
     description: The service zone's geo zones.