Set an environment variable for the menu light/dark state

[gilbarbara]

Hey!

I've seen that you can set the color for dark/light menus, but it would great to have the same option for images too.
Maybe an environment variable would be better for this case (and possible others).

Thanks~

[melonamin]

Adding env variable sounds good to me, added #87

As for different images, probably yes? Honestly I don't have opinion on that, I mostly use SF Symbols and it's look great in light\dark :).

[gilbarbara]

The env variable is perfect, thank you