[bug#48126] [PATCH] Add package for vim-solarized

[Tissevert]

Hello again,

I'm sorry I've just noticed that I set the wrong license in my package, I
hadn't checked it at the time when I first wrote it and forgot to edit it today
when I cleaned and sent it. Trouble is, I have no idea what the actual license 
is:

From Ethan Schoonover's original repository[1] it seems to be the MIT license 
but

- I can't find it in guix/license.scm, is that even an admissible free license ?
- The existing emacs-solarized-theme[2] package shipped with guix is distributed
  under a gpl3 license ?! (how is that possible ? can one redistribute software
  under a different license than its original one ? I assume it's because
  solarized-emacs is builds on solarized but adds something more ?) Then, I see
  that the main solarized repository imported an emacs theme[3] (a different one
  it seems) and put it under the MIT license as well…

Can we distribute vim-solarized ? If yes, under what license ? If not, do I
have to build a separate independant vim color theme for solarized and version
it under a free license like bbatsov did ?

[1]: https://github.com/altercation/solarized
[2]: https://github.com/bbatsov/solarized-emacs
[3]: https://github.com/altercation/solarized/tree/master/emacs-colors-solarized

Tissevert