Support ANSI terminal color escape codes

[sig-kill]

(terminal color escape codes being " ^[[0;31m " and similar)

There are some mentions of CSI ANSI in the source and docs (https://github.com/norcalli/nvim-colorizer.lua/search?q=ansi&unscoped_q=ansi) but as far as I can tell this isn't actually implemented.

[DanielCohenHillel]

Where does this stand? I would really like to use this 😄

[Shatur]

Very nice feature. I currently use colorizer for it, but it would be nice to use only this plugin.

[HrvojeFER]

+1 for this :)