fix: update navigation icons

Author: goosewin

fern/docs.yml

@@ -321,7 +321,6 @@ navigation:
                 icon: fa-light fa-arrow-right-arrow-left
 
       - section: Chat
-        icon: fa-light fa-comments
         contents:
           - page: Quickstart
             path: chat/quickstart.mdx
@@ -334,7 +333,7 @@ navigation:
             icon: fa-light fa-stream
           - page: OpenAI compatibility
             path: chat/openai-compatibility.mdx
-            icon: fa-brands fa-openai
+            icon: fa-light fa-puzzle-piece
 
       - section: Webhooks
         collapsed: true