added docs, also fixed doc break from global grid entity
added docs, also fixed doc break from global grid entity

joshua-cogliati-inl/raven,idaholab/raven,joshua-cogliati-inl/raven,joshua-cogliati-inl/raven,joshua-cogliati-inl/raven,joshua-cogliati-inl/raven,idaholab/raven,idaholab/raven,joshua-cogliati-inl/raven,idaholab/raven,idaholab/raven,joshua-cogliati-inl/raven,idaholab/raven,idaholab/raven