Submodules no longer build the correct file structure

[pvarin-figure]

Previously the command

pybind11-stubgen module1.module2.module3

would create the directory structure

module1/module2/module3/__init__.pyi

Now it creates a single directory with the following name:

module1.module2.module3/__init__pyi

Is this the intended behavior in the new release?

[sizmailov]

Thanks for catching this!