[Feature request] Add Go To Definition for stdlib exported code

[manhld0206]

Not sure if it possible but it would be very nice to be able to inspect how code exported from stdlib is implemented. Right now we can only see the definition when hover but can't go to the definition (like python)

[josiahls]

It would be nice to have support here. If I have the repo cloned, would be nice to point the extension to the stdlib path.