feat(module): add support for vue using unplugin (#2416)

Co-authored-by: Benjamin Canac <canacb1@gmail.com>

src/runtime/vue/plugins/color-mode.ts

@@ -0,0 +1,8 @@
+import { useDark } from '@vueuse/core'
+import type { Plugin } from 'vue'
+
+export default {
+  install() {
+    useDark()
+  }
+} satisfies Plugin

src/runtime/vue/plugins/head.ts

@@ -0,0 +1,8 @@
+import { createHead } from '@unhead/vue'
+import type { Plugin } from 'vue'
+
+export default {
+  install(app) {
+    app.use(createHead())
+  }
+} satisfies Plugin