Update server.en.yml (#27286)

* Update server.en.yml

Added "sidebar" and "header pulldown" keywords to the navigation_menu site setting

* Update server.en.yml

fixed typo pulldown -> dropdown

config/locales/server.en.yml

@@ -2759,7 +2759,10 @@ en:
         - "deactivated"
         - "inactive"
         - "unactivated"
-
+      navigation_menu: 
+        - "sidebar" 
+        - "header dropdown"
+        
     placeholder:
       discourse_connect_provider_secrets:
         key: "www.example.com"