Remove useless setup

Fix stubgen

Add generation of Python stubs

Additional doc fix

Fix naming

Fix compatibility with Boost.Python >= 1.77

badges: add PyPI

Move block to set OPTIONS before including base.cmake

Setting INSTALL_DOCUMENTATION OFF wasn't respected as it was overridden
in post-project.cmake which gets called upon setting PROJECT(). Moving
the settings prior to the include of base.cmake, it works as intended.