Include the color config for mako from ~/.local/state/mako/style instead
of hardcoding it or templating it into the config file.
This means we have to ensure the directory and file exist before running
mako which we do with an `env.d` startup script.
In preparation for at some point leaving flavours in favour of tinty
(since flavours is not maintained anymore), started preparing a rough
translation of the config file for the new program. One of the things I
changed (to make more semantic sense) is the zathura colorscheme file
name.
Switching from my custom, brittle, styling implementation `styler` to
the wonder `flavours` program which does exactly the same only with more
clarity, faster and - I would presume - more stable.