feat(nuxt-link): add isExternal to slot props

packages/nuxt/src/app/components/nuxt-link.ts

@@ -265,6 +265,7 @@ export function defineNuxtLink (options: NuxtLinkOptions) {
             route: router.resolve(href!),
             rel,
             target,
+            isExternal,
             isActive: false,
             isExactActive: false
           })