Slightly clarify floor docs
Slightly clarify floor docs

sjparker/OpenShadingLanguage,mcanthony/OpenShadingLanguage,brechtvl/OpenShadingLanguage,lgritz/OpenShadingLanguage,aconty/OpenShadingLanguage,fpsunflower/OpenShadingLanguage,sjparker/OpenShadingLanguage,fpsunflower/OpenShadingLanguage,gzorin/OpenShadingLanguage,svenstaro/OpenShadingLanguage,lgritz/OpenShadingLanguage,gzorin/OpenShadingLanguage,johnhaddon/OpenShadingLanguage,johnhaddon/OpenShadingLanguage,aconty/OpenShadingLanguage,johnhaddon/OpenShadingLanguage,rlmh/OpenShadingLanguage,fpsunflower/OpenShadingLanguage,lgritz/OpenShadingLanguage,aconty/OpenShadingLanguage,amartinez-cg/OpenShadingLanguage,juvenal/OpenShadingLanguage,gzorin/OpenShadingLanguage,sjparker/OpenShadingLanguage,imageworks/OpenShadingLanguage,lgritz/OpenShadingLanguage,fpsunflower/OpenShadingLanguage,yaroslav-tarasov/OpenShadingLanguage,brechtvl/OpenShadingLanguage,imageworks/OpenShadingLanguage,aconty/OpenShadingLanguage,svenstaro/OpenShadingLanguage,juvenal/OpenShadingLanguage,mcanthony/OpenShadingLanguage,imageworks/OpenShadingLanguage,amartinez-cg/OpenShadingLanguage,amartinez-cg/OpenShadingLanguage,svenstaro/OpenShadingLanguage,juvenal/OpenShadingLanguage,rlmh/OpenShadingLanguage,juvenal/OpenShadingLanguage,mcanthony/OpenShadingLanguage,brechtvl/OpenShadingLanguage,imageworks/OpenShadingLanguage,sjparker/OpenShadingLanguage,gzorin/OpenShadingLanguage,brechtvl/OpenShadingLanguage,amartinez-cg/OpenShadingLanguage,mcanthony/OpenShadingLanguage,yaroslav-tarasov/OpenShadingLanguage,aconty/OpenShadingLanguage,lgritz/OpenShadingLanguage,gzorin/OpenShadingLanguage,yaroslav-tarasov/OpenShadingLanguage,rlmh/OpenShadingLanguage,yaroslav-tarasov/OpenShadingLanguage,svenstaro/OpenShadingLanguage,imageworks/OpenShadingLanguage,johnhaddon/OpenShadingLanguage,amartinez-cg/OpenShadingLanguage,rlmh/OpenShadingLanguage,brechtvl/OpenShadingLanguage