Support index file on other project with ln -s

there’s two project, called frontend and backend. developed in different language.
I use ln -s to make a link from backend’s root folder to frontend/backend_folder.

but there’s a bit problem that, the cursor detect backend_folder as a file.
so cursor cannot access files under backend_folder.

when we do some crud job, there will be better if cursor can index the file under the soft link.