KERNEL-13948 docs: 修复combo_group demo接口错误

demo/js/core/abstract/combination/demo.combo_group.js

@@ -12,7 +12,7 @@ Demo.Func = BI.inherit(BI.Widget, {
             height: 25,
             iconCls: "close-ha-font"
         },
-        children: [{
+        items: [{
             type: "bi.single_select_item",
             height: 25,
             text: "一月",
@@ -63,7 +63,7 @@ Demo.Func = BI.inherit(BI.Widget, {
             },
             width: 200
         });
-        childCombo.setValue(BI.deepClone(this.child)[0].children[0].value);
+        childCombo.setValue(BI.deepClone(this.child)[0].items[0].value);
 
         return BI.createWidget({
             type: "bi.left",