DOC: More copy-editing of 'partition' docstring.
DOC: More copy-editing of 'partition' docstring.

[skip actions] [skip travis] [skip azp]

endolith/numpy,mhvk/numpy,numpy/numpy,numpy/numpy,mattip/numpy,mattip/numpy,numpy/numpy,charris/numpy,endolith/numpy,charris/numpy,numpy/numpy,endolith/numpy,mhvk/numpy,mhvk/numpy,mattip/numpy,charris/numpy,mhvk/numpy,endolith/numpy,mhvk/numpy,mattip/numpy,charris/numpy