graftee is a theme for people who can not programming.
To add some files in the WordPress, you must have knowledge of programming.
So graftee examines the presence or absence of a particular file, you have to create a mechanism to be used if it exists.
That is, there is no functions.php, but you can create a child theme stuck.
This file displays the news in dashboard in admin page.
For example, your made plugin fit this theme, so tell the theme user.
How to make, please create a news-sample.php to reference.