🖌 Added support for custom themes!

[lewisdoesstuff]

🖌 Custom Themes

Added support for custom themes without editing the main app.css file.

• Themes configurable through config.js, with several pre-included themes.

Some of these don't map particularly well to the limited selection of colors we use, but I've done what I can to match them.

Some themes only have a dark mode variant, so this is copied onto the light theme as well.

Again, if this is outside of the scope of this, just let me know and close this off :)