How unread and relevant news should be presented when running home-manager build and home-manager switch.
The options are
silent : Do not print anything during build or switch. The home-manager news command still works for viewing the entries.
notify : The number of unread and relevant news entries will be printed to standard output. The home-manager
news command can later be used to view the entries.
show : A pager showing unread news entries is opened.