Method for "extending" existing ES Module documentation?

[JustinGrote]

Say I have a package that has typescript types but they have no jsdoc/tsdoc so I only get basic intellisense without descriptions. Does TSDoc support a way for me to write my own docs and have them merged with the existing types from the package? Assuming esmodules with import syntax

Can @packageDocumentation be used this way without defining new types? Interface merges perhaps?