docs: support detecting broken link cross-projects (#10483)

* docs: support detecting broken link cross-projects

* remove double separators

www/apps/api-reference/markdown/store.mdx

@@ -831,7 +831,7 @@ If you click on the workflow, you'll view a reference of that workflow, includin
 
 This is useful if you want to extend an API route and pass additional data or perform custom actions.
 
-Refer to [this guide](https://docs.medusajs.com/learn/customization/extend-features/extend-create-product) to find an example of extending an API route.
+Refer to [this guide](!docs!/learn/customization/extend-features/extend-create-product) to find an example of extending an API route.
 
 <Feedback
   event="survey_api-ref"