I have the same issue for some of the libraries. I'm just starting with TS so it can be user error. However, I found that you can download the typings in the ID

I have the same issue for some of the libraries. I'm just starting with TS so it can be user error. However, I found that you can download the typings in the IDE in Settings/Javascripts/Libraries and download... This is tedious to have to do this though. Note: doing this works with normal JS as well which is pretty cool.