Here says,

Maybe there should mention exported types as well. And it could be guaranteed by a lint rule.

I find that revive could do it, which is already enabled in this project so no new dependence will be introduced. I just checked it in my local environment and there are up to 20+ methods and types missing godoc comments.

I just want to check that if exported Vars and Consts need to be documented.

And, if you think it's a good idea, I could be of some help to implement it.