docs: guide setup (#10862)

apps/guide/src/lib/source.ts

@@ -0,0 +1,7 @@
+import { loader } from 'fumadocs-core/source';
+import { docs } from '../../.source';
+
+export const source = loader({
+	baseUrl: '/guide',
+	source: docs.toFumadocsSource(),
+});