vim: remove unused plugins and set up indentation for .md properly

config/nvim/after/syntax/markdown.vim

@@ -37,3 +37,5 @@ delcommand HiLink
 if exists('old_syntax')
   let b:current_syntax = old_syntax
 endif
+
+setlocal ts=2 sts=2 sw=2 expandtab

config/nvim/init.vim

@@ -18,10 +18,6 @@ Plug 'ntpeters/vim-better-whitespace'
 Plug 'tpope/vim-vinegar'
 Plug 'jeffkreeftmeijer/vim-dim'
 
-" Git
-Plug 'tpope/vim-fugitive'
-Plug 'airblade/vim-gitgutter'
-
 "Better syntax
 Plug 'lervag/vimtex', {'for': 'tex'}
 Plug 'vivien/vim-linux-coding-style'