Preloading fonts to reduce request chaining

Added the right incantation to get fonts to pre-load, reducing request chaining by one hop.

Note, crossorigin is required even though it’s from the same domain, else the browser will not use them and redownload them when the stylesheet arrives.

<link rel="preload" href="/library/misc/fonts/Inter/Regular.woff2" as="font" type="font/woff2" crossorigin>
    <link rel="preload" href="/library/misc/fonts/Inter/Bold.woff2" as="font" type="font/woff2" crossorigin>
    <link rel="preload" href="/library/misc/fonts/Source_Serif/Regular.woff2" as="font" type="font/woff2" crossorigin>
    <link rel="preload" href="/library/misc/fonts/Source_Serif/Italic.woff2" as="font" type="font/woff2" crossorigin>