title: How to extend NuxtRuntimeConfig interface in typescript
body: <p>I am adding a variable in nuxt <code>$config</code> variable like in the <a href="https://nuxtjs.org/docs/2.x/directory-structure/nuxt-config#runtimeconfig" rel="nofollow noreferrer">docs</a>. This works.</p>
  <p>I am trying to let typescript know about this change.</p>
  <p>In my <code>nuxt.config.js</code> I have :</p>
  <pre class="lang-js prettyprint-override"><code>// nuxt.config.js. This is to add the variable
    publicRuntimeConfig: {
      baseUrl: process.env.URL || 'http://localhost:3000',
    }
  </code></pre>
  <p>I tried to extend the interface like this</p>
  <pre class="lang-js prettyprint-override"><code>// vue.shim.ts
  declare module '@nuxt/types' {
    interface NuxtRuntimeConfig {
      baseUrl: string
    }
  }
  </code></pre>
  <p>However vscode still does not pickup the change</p>
  <pre class="lang-js prettyprint-override"><code>const { $content, route, $config } = useContext()
  console.log($config.baseUrl) // typescript does not no about baseUrl, but it exists
  </code></pre>