RFE: add stuptools target which would allow install documentation (install_sphinx?)

[kloczek]

At the moment it is possible to build documentation in any format by use "setup.py build_sphinx -b ' but that it is only about generate documentation.

For example I'm trying to generate and install documentation generated by sphinx as roff man pages so I'm using setup.py build_sphinx -b man however after that seems like is missing possibility to install that documentation.

I think that it would be good to have something like setup.py install_sphinx -b <format> --root </install/root>

[kloczek]

As same as #9517 I thing that this ticket can be closed now.

[tk0miya]

Okay, closing now.