preload prefetch preconnect

https://medium.com/reloading/preload-prefetch-and-priorities-in-chrome-776165961bbf https://3perf.com/blog/link-rels/ https://blog.fundebug.com/2019/04/11/understand-preload-and-prefetch/ https://www.keycdn.com/blog/resource-hints https://developer.chrome.com/docs/devtools/network/reference/

https://www.w3.org/TR/resource-hints/