增加文件预览示例

package.json

@@ -25,6 +25,9 @@
     "@imengyu/vue3-context-menu": "^1.4.2",
     "@tinymce/tinymce-vue": "^6.0.1",
     "@visactor/vchart": "^1.11.10",
+    "@vue-office/docx": "^1.6.2",
+    "@vue-office/excel": "^1.7.11",
+    "@vue-office/pdf": "^2.0.2",
     "@vueuse/components": "^10.11.1",
     "@vueuse/core": "^10.11.0",
     "@vueuse/integrations": "^10.11.0",