fix linting

Author: schickling

packages/@contentlayer/experimental-source-files-stackbit/src/__test__/fixtures/next-starter/stackbit.yaml

@@ -1,7 +1,7 @@
 stackbitVersion: ~0.5.0
 cmsName: git
 ssgName: nextjs
-nodeVersion: "16"
+nodeVersion: '16'
 dataDir: content/data
 pagesDir: content/pages
 pageLayoutKey: type
@@ -13,5 +13,5 @@ assets:
 contentModels:
   Page:
     isPage: true
-    urlPath: "/{slug}"
-    newFilePath: "{slug}.md"
+    urlPath: '/{slug}'
+    newFilePath: '{slug}.md'