title: How to speed up fetching MediaItem with gatsby-source-wordpress?
body: <p>I'm building with Gatsby + WordPress, and the WP media library has 1000+ items; this takes a <em>very</em> long time to download during every fresh build:</p>
  <p><a href="https://i.stack.imgur.com/XZ3qv.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/XZ3qv.png" alt="gatsby-source-wordpress downloading MediaItem" /></a></p>
  <p>How can I have gatsby-source-wordpress fetch multiple images simultaneously? It appears that it fetches them sequentially.</p>
  <p>My current <strong>gatsby-config.js</strong> options for gatsby-source-wordpress:</p>
  <pre><code>resolve: `gatsby-source-wordpress`,
  options: {
    // the only required plugin option for WordPress is the GraphQL url.
    url: process.env.WPGRAPHQL_URL,
    schema: {
      timeout: 30000,
      perPage: 500,
      requestConcurrency: 50,
    },
    type: {
      MediaItem: {
        localFile: {
          requestConcurrency: 200,
        },
      },
    },
  },
  </code></pre>
  <p>Wondering if this is a frontend tweak needed, or something to adjust server-side.</p>
  <p>The <code>requestConcurrency: 200</code> setting in <code>localFile</code> doesn't appear to affect anything here.</p>