message: docs(TreeSelect): improve document
diff: @@ -174,7 +174,7 @@ export default {
  | Attribute | Description | Type | Default |
  | --- | --- | --- | --- |
  -| items | Required datasets for the component | _Item[]_ | `[]` |
  +| items | Required datasets for the component | _TreeSelectItem[]_ | `[]` |
  | height | Height | _number \| string_ | `300` |
  | main-active-index | The index of selected parent node | _number \| string_ | `0` |
  | active-id | Id of selected item | _number \| string \|<br>(number \| string)[]_ | `0` |
  @@ -184,9 +184,9 @@ export default {
  ### Events
  | Event | Description | Arguments |
  -| --- | --- | --- |
  -| click-nav | Emitted when parent node is selected | index: index of selected parent |
  -| click-item | Emitted when item is selected | data: selected item |
  +| ---------- | ------------------------------------ | ----------------------- |
  +| click-nav | Emitted when parent node is selected | _index: number_ |
  +| click-item | Emitted when item is selected | _item: TreeSelectChild_ |
  ### Slots
  @@ -194,9 +194,9 @@ export default {
  | ------- | -------------------- |
  | content | Custom right content |
  -### Data Structure of Item
  +### Data Structure of TreeSelectItem
  -`items` should be an array contains specified tree objects.
  +`TreeSelectItem` should be an array contains specified tree objects.
  In every tree object, `text` property defines `id` stands for the unique key while the `children` contains sub-tree objects.
  