performance

https://web.archive.org/web/20220826105904/https://browserdiet.com/
https://developer.mozilla.org/en-US/docs/Glossary/IIFE
https://medium.com/@sagarbawane/the-placement-of-script-tags-in-html-choosing-between-top-and-bottom-70c975d1d91b
https://developer.mozilla.org/en-US/docs/Web/HTML/Attributes/rel/preconnect