message: add the missing "as" to the preload link animation.
diff: %sapper.base%
  - <link rel="stylesheet" rel="preload" href="font.css" />
  + <link rel="stylesheet" rel="preload" href="font.css" as="style" />
  <link rel="stylesheet" href="global.css" />
  <link rel="stylesheet" href="styles.css" />
  <link rel="manifest" href="manifest.json" crossorigin="use-credentials" />
  