docs:添加订单领域服务

+version: v1
+kind: Method
+metadata:
+  name: cancel
+  type: command
+  description: 取消订单领域服务
+  payload:
+  - ref: orderNo
+    required: true
+  result:
+  - name: order
+    type: 
+      schema: order

+version: v1
+kind: Method
+metadata:
+  name: return
+  type: command
+  description: 订单退货领域服务
+  payload:
+  - ref: orderNo
+    required: true
+  result:
+  - name: order
+    type: 
+      schema: order