chore: update sidebar label to Vapi Guides

Author: goosewin

fern/docs.yml

@@ -105,7 +105,7 @@ navigation:
           - page: Web calls
             icon: fa-light fa-browser
             path: quickstart/web.mdx
-          - page: Vapi Cookbook
+          - page: Vapi Guides
             icon: fa-light fa-book-open
             path: guides.mdx