Install unity-scope-yelp by entering the following commands in the terminal:
sudo apt update sudo apt install unity-scope-yelp
Description:
Help scope for Unity
This package contains the "yelp" scope which allows Unity to search help documentation.
Homepage: https://launchpad.net/unity-scope-yelp
Version: 0.1+13.10.20130723-0ubuntu1
Section: universe/gnome