docs: fix RouteMeta typing example (#883)

Without this change the example would have no exported members other than RouteMeta

diff --git a/docs/guide/advanced/meta.md b/docs/guide/advanced/meta.md
index 07ecb5fc64f7fad81914fa10dd3e714ebce25de5..17a290e7d3fddf3a861a4bd6be916138445ed930 100644 (file)
--- a/docs/guide/advanced/meta.md
+++ b/docs/guide/advanced/meta.md
@@ -56,6 +56,8 @@ router.beforeEach((to, from) => {
 It is possible to type the meta field by extending the `RouteMeta` interface:
 
 ```ts
+import 'vue-router'
+
 declare module 'vue-router' {
   interface RouteMeta {
     // is optional