Update display name to "What's New?"

https://claude.ai/code/session_01PKuW5yr6fMdr6mSwX5Gchy

Author: claude

fern/docs.yml

@@ -76,7 +76,7 @@ tabs:
     icon: fa-light fa-square-terminal
     slug: cli
   changelog:
-    display-name: What's New
+    display-name: What's New?
     slug: whats-new
     changelog: ./changelog
     icon: history