docs: clarify which setting for the "binding" directive does what
docs: clarify which setting for the "binding" directive does what

da-woods/cython,cython/cython,cython/cython,da-woods/cython,ChristopherHogan/cython,scoder/cython,scoder/cython,scoder/cython,ChristopherHogan/cython,da-woods/cython,da-woods/cython,ChristopherHogan/cython,scoder/cython,cython/cython,cython/cython