Synchronize RGB Hex values from official Nord palette

Borrowed from nordtheme/iterm2#16.

Author: ericvw

colors/nord.vim

@@ -167,8 +167,8 @@ if has('nvim')
   let g:terminal_color_8 = s:nord3_gui
   let g:terminal_color_9 = s:nord11_gui
   let g:terminal_color_10 = s:nord14_gui
-  let g:terminal_color_11 = s:nord13_gui
-  let g:terminal_color_12 = s:nord9_gui
+  let g:terminal_color_11 = s:nord12_gui
+  let g:terminal_color_12 = s:nord10_gui
   let g:terminal_color_13 = s:nord15_gui
   let g:terminal_color_14 = s:nord7_gui
   let g:terminal_color_15 = s:nord6_gui