This seems to be a relatively new feature given the age of this post.
I stumbled across this while messing around in Roblox Studio. It seems that docstring capability has been added to studio, but not much has been reported on it yet.
This implementation of docstrings also seems to not follow the javadoc standard of @param / @return or the sphinx standard of :param / :return as markup does not seem to be implemented.
As with most things Roblox, I'd recommend utilizing the docstrings on Roblox methods - as OP mentions in his post - as example of what to do until community standards take precedent.
