refactor: add loading component and demo

vben

2020-12-01 5db3ce773793d06fa17336aca42470d2aae93fb8

 src/router/menus/modules/demo/comp.ts

@@ -45,6 +45,10 @@
        name: 'routes.demo.comp.upload',
      },
      {
        path: 'loading',
        name: 'routes.demo.comp.loading',
      },
      {
        path: 'scroll',
        name: 'routes.demo.comp.scroll',
        children: [