Add link to civix

docs/hooks/hook_civicrm_navigationMenu.md

@@ -16,7 +16,7 @@ This hook is called after the menus are rebuilt.
 You can use this hook to add new menu, add children to new menu and get the list of menu items for any parent.
 
 !!! note "Use the Civix implementation"
-    civix comes with helper functions `_EXTENSION_NAME_civix_insert_navigation_menu` and `_EXTENSION_NAME_civix_navigation_menu` that simplify the process of inserting menu items. Consider using these functions rather than using the examples below or writing your own implementation of this hook.
+    [Civix](/extensions/civix.md) comes with helper functions `_EXTENSION_NAME_civix_insert_navigation_menu` and `_EXTENSION_NAME_civix_navigation_menu` that simplify the process of inserting menu items. Consider using these functions rather than using the examples below or writing your own implementation of this hook.
 
 ## Definition