docs(llms): generate llms.txt from content (#3246)

docs/modules/llms/runtime/server/routes/llms.txt.get.ts

@@ -0,0 +1,56 @@
+import { joinURL } from 'ufo'
+import type { ModuleOptions } from '~~/modules/llms/module'
+
+export default eventHandler(async (event) => {
+  const options = useRuntimeConfig(event).llms as ModuleOptions
+
+  const llms = [
+    `# ${options.title || 'Documentation'}`
+  ]
+
+  if (options.description) {
+    llms.push(`> ${options.description}`)
+  }
+
+  llms.push(
+    '## Documentation Sets',
+    `- [Complete Documentation](${joinURL(options.domain, '/llms_full.txt')}): The complete documentation including all content`
+  )
+
+  for (const section of options.sections) {
+    // @ts-expect-error - typecheck does not derect server querryCollection
+    const query = queryCollection(event, section.collection)
+      .select('path', 'title', 'description')
+      .where('path', 'NOT LIKE', '%/.navigation')
+
+    if (section.filters) {
+      for (const filter of section.filters) {
+        query.where(filter.field, filter.operator, filter.value)
+      }
+    }
+
+    const docs = await query.all()
+
+    const links = docs.map((doc) => {
+      return `- [${doc.title}](${joinURL(options.domain, doc.path)}): ${doc.description}`
+    })
+
+    llms.push(`## ${section.title}`)
+
+    if (section.description) {
+      llms.push(section.description)
+    }
+
+    llms.push(links.join('\n'))
+  }
+
+  if (options.notes && options.notes.length) {
+    llms.push(
+      '## Notes',
+      (options.notes || []).map(note => `- ${note}`).join('\n')
+    )
+  }
+
+  setHeader(event, 'Content-Type', 'text/plain')
+  return llms.join('\n\n')
+})