title: Unable to use $fetchState in Nuxt 2.12
body: <p>So I'm trying to use the new functionality describe in the documentation.</p>
  
  <p>However I'm ending up getting this error :</p>
  
  <blockquote>
    <p>Property or method "$fetchState" is not defined on the instance but referenced during render.</p>
  </blockquote>
  
  <p>Even though my component define clearly the fetch() method and I manage to get something out of it.</p>
  
  <pre><code>&lt;template&gt;
      &lt;div v-if="$fetchState"&gt;
          &lt;p v-if="$fetchState.pending"&gt;Fetching posts...&lt;/p&gt;
          &lt;p v-else-if="$fetchState.error"&gt;Error while fetching posts&lt;/p&gt;
          &lt;div v-else&gt;
              &lt;div v-if="content.content1" v-html="content.content1" /&gt;
              &lt;div v-if="content.content2" v-html="content.content2" /&gt;
          &lt;/div&gt;
      &lt;/div&gt;
  &lt;/template&gt;
  &lt;script&gt;
  import { mapState } from 'vuex'
  
  export default {
      async fetch({ store, error }) {
          try {
              await store.dispatch('home/fetchContent')
          } catch (e) {
              error({
                  statusCode: 503,
                  message: 'Unable to fetch'
              })
          }
      },
      computed: mapState({
          content: (state) =&gt; state.home.content
      })
  }
  &lt;/script&gt;
  
  </code></pre>
  
  <p>Has anybody ever encountered that before ?</p>