update the dir oragnization

docs/.vuepress/config.js

@@ -79,6 +79,10 @@ module.exports = {
                 text: '应用框架',
                 link: '/doc/apparch/'
             },
+            {
+                text: '应用案例',
+                link: '/doc/appcase/'
+            },
             {
                 text: '快速上手',
                 link: '/doc/appdev/',

docs/doc/appcase/README.md

@@ -0,0 +1,7 @@
+# 应用案例
+
+---
+
+- [大胜达智能环境感知系统](/doc/appcase/dashengda.md)
+
+- [钱江电气智能电力监控系统](/doc/appcase/qianjiangdianqi.md)