Add call concurrency page to docs navigation

Co-authored-by: sahil <sahil@vapi.ai>

Author: cursoragent

fern/docs.yml

@@ -411,23 +411,26 @@ navigation:
                 path: calls/customer-join-timeout.mdx
               - page: Voicemail detection
                 path: calls/voicemail-detection.mdx
-          - section: Transfer calls
-            icon: fa-light fa-phone-arrow-right
-            contents:
-              - page: Call forwarding
-                path: call-forwarding.mdx
-              - page: Assistant-based warm transfer
-                path: calls/assistant-based-warm-transfer.mdx
-              - page: Dynamic call transfers
-                path: calls/call-dynamic-transfers.mdx
-              - page: On-hold specialist transfer
-                path: calls/call-handling-with-vapi-and-twilio.mdx
-              - page: Debug forwarding drops
-                path: calls/troubleshoot-call-forwarding-drops.mdx
-                icon: fa-light fa-bug
-          - page: Call queue management
-            path: calls/call-queue-management.mdx
-            icon: fa-light fa-phone-office
+            - section: Transfer calls
+              icon: fa-light fa-phone-arrow-right
+              contents:
+                - page: Call forwarding
+                  path: call-forwarding.mdx
+                - page: Assistant-based warm transfer
+                  path: calls/assistant-based-warm-transfer.mdx
+                - page: Dynamic call transfers
+                  path: calls/call-dynamic-transfers.mdx
+                - page: On-hold specialist transfer
+                  path: calls/call-handling-with-vapi-and-twilio.mdx
+                - page: Debug forwarding drops
+                  path: calls/troubleshoot-call-forwarding-drops.mdx
+                  icon: fa-light fa-bug
+            - page: Call queue management
+              path: calls/call-queue-management.mdx
+              icon: fa-light fa-phone-office
+            - page: Call concurrency
+              path: calls/call-concurrency.mdx
+              icon: fa-light fa-gauge-high
           - page: Call end reasons
             path: calls/call-ended-reason.mdx
             icon: fa-light fa-phone-hangup