Dark mode support

[adigitoleo]

Dark mode teaser:

I will try to use the existing palette as much as possible, but some of the darker colors will eventually need to be replaced. So the dark theme will probably get its own 16 colors.

Inspiration and alternatives:

• vim-farout
• yuejiu
• colibri - it's very purple, but the contrast/lack of really bright colors is nicei
• aerique - for emacs, maybe it has vim support?
• alduin
• ... (there are many dark themes, I will need to hunt for the minimalist ones)

[adigitoleo]

Experimental dark mode is live on the darkmode branch. For vim-plug, you will need to change the plugin line:

Plug 'adigitoleo/vim-mellow', {'branch': 'darkmode'}

[adigitoleo]

Update: I now have a separate darkmode palette that I am happier with, and will be migrating to these colors for a revised dark mode. It is now somewhat different from the above screenshot...

[adigitoleo]

Dark mode added in #2