Update Readme.

Update Readme to reflect the fact that NeoVim now has a `termguicolors`
option. Make some other minor changes to the text.

Readme.md

@@ -13,14 +13,20 @@ colors cannot be used with versions of Vim supporting true-color terminals.
 
 This color scheme works **out of the box** if you use:
 
-- NeoVim with true-color support enabled, or
-- Vim 7.4.1799 or later with `termguicolors` on,
+- Vim 7.4.1799 or later,
+- NeoVim,
 
-*and* a true-color enabled terminal (e.g., iTerm). It also works in MacVim and other
-GUI versions, of course.
+**and** a true-color enabled terminal (e.g., [iTerm2](https://www.iterm2.com)).
+Just add the following line to your `.vimrc`:
 
-For terminals not supporting true colors, the requirement is the same as for
-the other colorschemes: your terminal ASCII colors must be set to the Solarized
+```
+set termguicolors
+```
+
+The color scheme also works in MacVim, gVim, etc…: no configuration is needed.
+
+For terminals not supporting true colors, the requirement is the same as for the
+other color schemes: your terminal ASCII colors must be set to the Solarized
 palette. The ugly degraded 256-color variant has been removed.