This code includes 4 separate snippets which you need to paste into 3 different files to achieve something like this.
functions.php – Paste the code which includes the template-tags.php file and conditionally hooks in the template tag using the genesis_entry_content hook which can be changed to any other theme specific or WordPress hook like the_content()
template-tags.php – Create a new file name template-tags.php and paste all the code into this new file including the opening php tag. Upload this file to your child themes root directory.
style.css – Add this sample CSS code which can be easily modified near the end of your child themes style.css file before the Media Queries section.
You need to subscribe to fully access this tutorial.