If you really want to put it into the unity package I would prefer the installation dialog as the docu is probably an unnecessary step for many of us, especially when you have multiple projects.

If I would have the choice I would still favor the download only solution.

You can always uncheck the .zip when importing the unitypackage. That way, the documentation won't be installed.

We want to solve this in v1.2.5, let's see.

Thanks!