refactor(projects): 路由声明重构，添加composables，BaseLayout进行中，文件夹规范

src/layouts/BaseLayout/components/common/index.ts

@@ -4,6 +4,16 @@ import GlobalFooter from './GlobalFooter/index.vue';
 import GlobalLogo from './GlobalLogo/index.vue';
 import GlobalMenu from './GlobalMenu/index.vue';
 import GlobalTab from './GlobalTab/index.vue';
+import HeaderPlaceholder from './HeaderPlaceholder/index.vue';
 import SettingDrawer from './SettingDrawer/index.vue';
 
-export { GlobalHeader, GlobalContent, GlobalFooter, GlobalLogo, GlobalMenu, GlobalTab, SettingDrawer };
+export {
+  GlobalHeader,
+  GlobalContent,
+  GlobalFooter,
+  GlobalLogo,
+  GlobalMenu,
+  GlobalTab,
+  HeaderPlaceholder,
+  SettingDrawer
+};