light mode

[nwztest]

add light mode and the ability to toggle between light and dark mode (this was available in 2023)

[icepcp]

i tried to implement this in astro last time however it did not go so well (light mode flashes before site turns into dark mode) however it is certainly possible. there will be a bit of pain points tho like adding dark: classes to every single element and ensuring that our partners logo are in the correct theme. once again - its def possible, but a lot of work