perf[Tinymce]: import tinymce from cdn (#1996)

src/components/Tinymce/index.vue

@@ -8,6 +8,10 @@
 </template>
 
 <script>
+/**
+ * docs:
+ * https://panjiachen.github.io/vue-element-admin-site/feature/component/rich-editor.html#tinymce
+ */
 import editorImage from './components/EditorImage'
 import plugins from './plugins'
 import toolbar from './toolbar'
@@ -101,6 +105,8 @@ export default {
       const _this = this
       window.tinymce.init({
         language: this.language,
+        // language cnd URL, detail see https://github.com/PanJiaChen/tinymce-lang
+        language_url: 'https://cdn.jsdelivr.net/npm/tinymce-lang/langs/zh_CN.js',
         selector: `#${this.tinymceId}`,
         height: this.height,
         body_class: 'panel-body ',