Use prism as smaller nicer code highlighting library

app/javascript/packs/application.js

@@ -13,7 +13,7 @@ require('tinyforms');
 require('demo');
 require('backend_typed');
 require('tabs');
-require('highlight');
+require('prism');
 
 // Uncomment to copy all static images under ../images to the output folder and reference
 // them with the image_pack_tag helper in views (e.g <%= image_pack_tag 'rails.png' %>)