Fix docs typos (#871)
Fix docs typos (#871)

Fixes #869
Fixes #870

[ci skip]
aconty/OpenShadingLanguage,lgritz/OpenShadingLanguage,aconty/OpenShadingLanguage,aconty/OpenShadingLanguage,aconty/OpenShadingLanguage,brechtvl/OpenShadingLanguage,imageworks/OpenShadingLanguage,brechtvl/OpenShadingLanguage,lgritz/OpenShadingLanguage,imageworks/OpenShadingLanguage,brechtvl/OpenShadingLanguage,imageworks/OpenShadingLanguage,lgritz/OpenShadingLanguage,lgritz/OpenShadingLanguage,brechtvl/OpenShadingLanguage,lgritz/OpenShadingLanguage,brechtvl/OpenShadingLanguage,imageworks/OpenShadingLanguage,imageworks/OpenShadingLanguage,aconty/OpenShadingLanguage