feat: toast-provider and useToast initial

docs/.vitepress/theme/index.js

@@ -4,4 +4,12 @@ import DefaultTheme from 'vitepress/theme'
 
 import './clear.css'
 
-export default DefaultTheme
+import { TransitionGroup } from "vue";
+
+export default {
+    ...DefaultTheme,
+    enhanceApp({ app, router, siteData }) {
+        // strange thing, but there is no global transition-group component inside vitepress app
+        app.component('TransitionGroup', TransitionGroup)
+    }
+}