Preloads the given link.
When the link is clicked later, the response will already be cached, making the interaction feel instant.
You may use this function to programmatically populate the cache with pages the user is likely to click or requires accessible while offline.
Preload requests are considered background requests and will not show the progress bar.
See options for up.follow()
.
Whether the preload request may be aborted when the user navigates
or when up.fragment.abort()
is called.
A promise that will be fulfilled when the request was loaded and cached.
When preloading is disabled the promise
rejects with an up.AbortError
.