chore: add docs site

docs/faq/async-action.md

@@ -0,0 +1,22 @@
+# How to use async data in metaInfo?
+
+`vue-meta` will do this for you automatically when your component state changes.
+
+Just make sure that you're using the function form of `metaInfo`:
+
+```js
+{
+  data () {
+    return {
+      title: 'Foo Bar Baz'
+    }
+  },
+  metaInfo () {
+    return {
+      title: this.title
+    }
+  }
+}
+```
+
+Check out the [vuex-async](https://github.com/nuxt/vue-meta/tree/master/examples/vuex-async) example for a more detailed demonstration