Navbar logo delay when switching away from default (dark) theme

[snowboardit]

When switching to light mode, there is a noticeable delay before the dark logo loads in. Preloading the dark logo should fix this, so when the theme is switched the new asset is ready to render without having to load first.

[snowboardit]

https://stackoverflow.com/questions/819336/how-to-preload-images-without-javascript

[snowboardit]

Looks like the logic that handles the url switching from light to dark logo is either in
Website-2023/themes/blowfish/assets/js/appearance.js
or
Website-2023/themes/blowfish/public/js/appearance.js