Flexoki Dynamic Theme wót Jost Alemann

Dynamic theme for firefox using the flexoki color scheme.

This contains a light and a dark theme. The theme automatically follows the operating systems preference.

I mostly stuck to the flexoki color scheme. However, I made the text colors in the dark theme 2 tones lighter for better contrast and readability. Also there might be alternative ways to use the colors that might look even better. Feel free to discuss changes in an Issue.