[Improvement] TreeSelect: support string type id (#1126)

packages/tree-select/en-US.md

@@ -51,7 +51,7 @@ export default {
 |-----------|-----------|-----------|-------------|
 | items | Required datasets for the component, see Data Structure for detail. | `Array` | `[]` |
 | main-Active-index | The index of selected parent node | `Number` | `0` |
-| active-id | Id of selected item | `Number` | `0` |
+| active-id | Id of selected item | `String | Number` | `0` |
 
 #### Event
 | Event | Description | Arguments |

packages/tree-select/index.vue

@@ -43,7 +43,7 @@ export default create({
       default: 0
     },
     activeId: {
-      type: Number,
+      type: [Number, String],
       default: 0
     },
     maxHeight: {

packages/tree-select/zh-CN.md

@@ -52,7 +52,7 @@ export default {
 |-----------|-----------|-----------|-------------|
 | items | 分类显示所需的数据，具体数据结构可看 数据结构 | `Array` | `[]` |
 | main-active-index | 左侧导航高亮的索引 | `Number` | `0` |
-| active-id | 右侧选择项，高亮的数据id | `Number` | `0` |
+| active-id | 右侧选择项，高亮的数据id | `String | Number` | `0` |
 
 #### 事件