switching between light and dark background automatically

[AndriiOmelianenko]

Expected Behavior

just duplicating an issue from old repo hidetatz/kubecolor#115

[applejag]

If we implement this, then I'd like our themes to have a non-light and non-dark variant, and then introduce an additional auto theme that will become the new default.

Logic should be as follows:

• auto preset: detect color and pick dark or light
• protanopia preset: detect and pick protanopia-dark or protanopia-light
• if detection fails, fall back to the dark variant.

Example library I found after a short Google that implements this detection: (albeit in Rust, but might be some Go variants available. On the other hand, shouldnt be too tricky to just port) https://github.com/Canop/terminal-light