sty: make surface option exclusivity clearer
sty: make surface option exclusivity clearer

poldracklab/preprocessing-workflow,oesteban/fmriprep,oesteban/fmriprep,oesteban/preprocessing-workflow,poldracklab/preprocessing-workflow,oesteban/preprocessing-workflow,poldracklab/fmriprep,poldracklab/fmriprep,oesteban/fmriprep,poldracklab/fmriprep