docs(website): fix sitemap (#97)

Author: gilgardosh

website/next-sitemap.config.cjs

@@ -6,5 +6,6 @@ const opts = {
   siteUrl: process.env.SITE_URL || 'https://the-guild.dev/graphql/sse',
   generateIndexSitemap: false,
   exclude: ['*/_meta'],
+  output: 'export',
 };
 module.exports = opts;