vim: add vim-corvine and vim-plan9 color schemes
vim: add vim-corvine and vim-plan9 color schemes

These are nice color schemes (especially for light backgrounds) that I
occasionally use when the room is bright, when I'm outside, or if I'm
just looking for a change of pace from base16-ocean.

jparise/dotfiles,jparise/dotfiles,jparise/dotfiles,jparise/dotfiles