Install hud-doc by entering the following commands in the terminal:
sudo apt update sudo apt install hud-doc
Description:
Backend for the Unity HUD
Unity HUD is a heads-up-display interface for controlling the behavior of applications as well as Unity via typed-in commands. It provides access to all applications menu via a single central interface, in order to simplify application usage and make menus more accessible. . This package contains developer documentation.
Homepage: http://launchpad.net/hud
Version: 14.10+17.10.20170619-0ubuntu2
Section: universe/doc