Add support for LS_COLORS through vivid about colortty

[shuhei]

I'm not familiar with LS_COLORS or details of terminal colors, but it seems that the theme files of vivid have arbitrary color names in colors. So, I'm not sure how to map alacritty colors to the colors in LS_COLORS.

One possible way to match colors of alacritty and LS_COLORS would be to use the 16 colors instead of exact color codes in LS_COLORS. Then, alacritty will render the 16 colors with its color scheme.

[orhanbalci]

Actually as far as i know there is not a one to one mapping between terminal colors and LS_COLORS. May be we can look at a well known terminal color theme and vivid configuration and find a mapping.
Monokai is a good example of this.

[shuhei]

I checked vivid themes and read about LS_COLORS. If we want to create LS_COLORS that match with Alacritty color theme, we need two information.

1. pick colors for file types (for example, make executable red)
2. use the exact colors from Alacritty color theme

(2) can be automatically achieved if LS_COLORS uses 3/4 bit colors. We can't automatically generate (1) for arbitrary color schemes. You can use an OS default LS_COLORS that uses 3/4-bit colors (for example dircolors command) or create one with more file types.

I'm closing this issue because I think it's out of the scope of converting Alacrtty color schemes.