1.将class定义方式修改为interface定义,方面未来扩展

2.补全失的导入导出类型

types/content.d.ts

@@ -2,7 +2,7 @@
 // Project: https://github.com/iview/iview
 // Definitions by: yangdan
 // Definitions: https://github.com/yangdan8/iview.git
-import Vue,{ VNode } from 'vue';
+import Vue, { VNode } from 'vue';
 
-export declare class Content extends Vue {
+export declare interface Content extends Vue {
 }