$ sudo apt-get update
$ sudo apt-get install libghc-gitit-data 

libghc-gitit-data is installed in your system.

Make ensure the libghc-gitit-data package were installed using the commands given below,

$ sudo dpkg-query -l | grep libghc-gitit-data *

You will get with libghc-gitit-data package name, version, architecture and description in a table

libghc-gitit-data package basic information: