Binary package “grass-doc” in ubuntu bionic

GRASS GIS user documentation

 Commonly referred to as GRASS, this is a Geographic Information
 System (GIS) used for geospatial data management and analysis,
 image processing, graphics/map production, spatial modeling, and
 visualization. GRASS is currently used in academic and commercial
 settings around the world, as well as by many government agencies
 and environmental consulting companies.
 .
 This package contains HTML documentation for the GRASS system.