接口名称：Filter_Plugin_Admin_ArticleMng_SubMenu
接口描述：文章管理页面增加子菜单
调用方法：
PHP
Add_Filter_Plugin('Filter_Plugin_Admin_ArticleMng_SubMenu','yt_demo');调用示例：
PHP
RegisterPlugin("yt_demo","ActivePlugin_demo");//注册插件function ActivePlugin_demo() {Add_Filter_Plugin('Filter_Plugin_Admin_ArticleMng_SubMenu','yt_demo');}function yt_demo(){
echo '<a href="?act=ArticleMng&category=8"><span class="m-left">随笔</span></a>';
echo '<a href="?act=ArticleMng&category=29"><span class="m-left">项目进度</span></a>';}效果展示：
