Install ruby-rouge by entering the following commands in the terminal:
sudo apt update sudo apt install ruby-rouge
Description:
pure-Ruby syntax highlighter compatible with pygments
Rouge is a pure-Ruby syntax highlighter. It can highlight over 60 languages, and output HTML or ANSI 256-color text. Its HTML output is compatible with stylesheets designed for pygments.
Homepage: http://rouge.jneen.net/
Version: 2.2.1-1
Section: universe/ruby