docs: use vuepress package in migration guide (#1245)

YagoLeo · web-flow · commit f33d4bb7ab31 · 2023-02-03T18:59:31.000+08:00
diff --git a/docs/guide/migration.md b/docs/guide/migration.md
@@ -47,7 +47,7 @@ Using a theme via string is not supported. Import the theme directly.
 -   },
 - }
 
-+ import { defaultTheme } from '@vuepress/theme-default'
++ import { defaultTheme } from 'vuepress'
 + export default {
 +   theme: defaultTheme({
 +     // default theme config
