docs: update vitepress

docs/src/.vitepress/theme/index.ts

@@ -1,8 +1,5 @@
-import type { Theme } from 'vitepress'
 import VueAnimXyz from '@animxyz/vue3'
-import DefaultTheme from 'vitepress/theme'
 import { inject } from '@vercel/analytics'
-import Layout from './layouts/default.vue'
 import 'virtual:windi.css'
 import '@animxyz/core'
 import '@vue-flow/core/dist/style.css'
@@ -11,13 +8,14 @@ import '@vue-flow/controls/dist/style.css'
 import '@vue-flow/minimap/dist/style.css'
 import './../../assets/index.css'
 
-const CustomTheme = {
-  ...DefaultTheme,
+import Theme from 'vitepress/theme'
+import Layout from './layouts/default.vue'
+
+export default {
+  extends: Theme,
   Layout,
-  enhanceApp: ({ app }) => {
+  enhanceApp({ app }) {
     app.use(VueAnimXyz)
     inject()
   },
-} as Theme
-
-export default CustomTheme
+}