RayZorYubo flarum-tags is an extension, and, as such, it renders the page with jsx, a JavaScript way of building up the elements for your page.
You can start to understand how to develop an extension, or modifying one, with the getting started tutorial in the docs. Flarum-tags is on github, so you can see the source code and find your way. If you need more help in developing, you can join the developer page on Gitter (chat button on the top)
