How to Add Categories and Tags to Pages in WordPress
Another way, and maybe the best way, is to create a child theme with a functions.php and insert the above snippet into it. A child theme requires a style.css so you can also make styling changes in it and nothing in your child theme will get overwritten by an update.
Thanks for the snippet, saved me a trip to the codex. It has been filed for future reference and will most likely be put in place on every site I build. (NOTE*, Your child functions.php needs an opening php tag before this snippet) Check the wordpress codex for more on creating a child theme. It’s one thing there that’s easy to find. Also, child themes don’t work on every theme, though they should. If a theme won’t take a child theme, I won’t use it.