add subscription

@@ -23,3 +23,12 @@ export const DELETE_CATEGORY = gql`
     deleteCategory(name: $name)
     deleteCategory(name: $name)
   }
   }
 `;
 `;
+
+export const SUBSCRIPTION_CATEGORY = gql`
+  subscription {
+    subCategory {
+      id
+      name
+    }
+  }
+`;