Refresh: Dynamic Favicon

[stephaniehobson]

It would be cool to have the favicon be on a transparent background. However this could be a can of browser compatibility worms because we don't know what colour it will end up on 😬

There are multiple ways to light and dark mode favicon icons. (I liked the media attribute way best) but additional contexts need to be considered (new tab favourites, search results, home screen bookmarks...).

If you dive into this and find it's more trouble than its worth to get this to work in all the places it needs to please just comment and close this issue as won't fix.

Success criteria:

• Favicon is dino flag
• Favicon visible in both light and dark mode
• Favicon works in supported browsers (ie. fallbacks exist where necessary)
• Favicon works in a variety of contexts (new tab favourites, search results, home screen bookmarks, etc.)