perf: 点击模板时请求数据，而不是点击预览时请求数据。这样点击预览时能立刻展示预览内容。

src/views/viewTemplate/components/TemplateListContainer.vue

@@ -47,14 +47,13 @@ export default class Index extends Vue {
     return this.selectedId !== null;
   }
 
-  handleClickItem(id: number) {
+  async handleClickItem(id: number) {
     this.selectedId = id;
+    const ret = await this.$api.template.get(id);
+    this.detail = JSON.parse(ret.detail);
   }
 
   async handleClickPreview() {
-    const id = this.selectedId;
-    const ret = await this.$api.template.get(id);
-    this.detail = JSON.parse(ret.detail);
     this.previewVisible = true;
   }