chore(users): Add @gatsbyjs as a user of this plugin

Author: MichaelDeBoey

other/USERS.md

@@ -3,6 +3,8 @@
 If you or your company uses this project, add your name to this list! Eventually
 we may have a website to showcase these (wanna build it!?)
 
+- [Gatsby](https://gatsbyjs.org) uses it in their
+  [website](https://github.com/gatsbyjs/gatsby/tree/master/www)
 - [Kent C. Dodds](https://kentcdodds.com) uses it in
   [his personal website](https://github.com/kentcdodds/kentcdodds.com)
 - [Anurag Hazra](https://anuraghazra.github.io) uses it in