Add Gitsigns and Sneak support (#316)

The highlighting for the marker of the `justinmk/vim-sneak` now matches
the style of the Vim search highlighting.
Also the inline text of the Neovim specific `lewis6991/gitsigns.nvim`
plugin now matches the the foregroun color of comments.


Co-authored-by: Sven Greb <development@svengreb.de>

GH-316

colors/nord.vim

@@ -573,6 +573,10 @@ if has('nvim')
     call s:hi("LspDiagnosticsUnderlineInformation" , s:nord8_gui, "", s:nord8_term, "", "undercurl", "")
     call s:hi("LspDiagnosticsUnderlineHint" , s:nord10_gui, "", s:nord10_term, "", "undercurl", "")
   endif
+
+  " Gitsigns
+  " > lewis6991/gitsigns.nvim
+  hi! link GitSignsCurrentLineBlame Comment
 endif
 
 " GitGutter
@@ -589,6 +593,10 @@ call s:hi("SignifySignChange", s:nord13_gui, "", s:nord13_term, "", "", "")
 call s:hi("SignifySignChangeDelete", s:nord11_gui, "", s:nord11_term, "", "", "")
 call s:hi("SignifySignDelete", s:nord11_gui, "", s:nord11_term, "", "", "")
 
+" Sneak
+" > justinmk/vim-sneak
+hi! link Sneak Search
+
 " fugitive.vim
 " > tpope/vim-fugitive
 call s:hi("gitcommitDiscardedFile", s:nord11_gui, "", s:nord11_term, "", "", "")