Add vim-gitgutter plugin and relevant config

Add gitgutter added/modified/removed count to statusbar

.gitmodules

@@ -43,3 +43,6 @@
 [submodule "extras/onehalf"]
 	path = extras/onehalf
 	url = https://github.com/sonph/onehalf.git
+[submodule "pack/plugins/start/vim-gitgutter"]
+	path = pack/plugins/start/vim-gitgutter
+	url = https://github.com/airblade/vim-gitgutter.git

pack/plugins/start/vim-gitgutter

@@ -0,0 +1 @@
+Subproject commit 24cc47789557827209add5881c226243711475ce

vimrc

@@ -8,6 +8,9 @@ set t_TI=""
 set t_TE=""
 set t_ut=""
 
+set updatetime=1000
+set signcolumn=yes
+
 colorscheme onehalfdark
 if exists('+termguicolors') && ($COLORTERM == "24bit" || $COLORTERM == "truecolor")
   let &t_8f = "\<Esc>[38;2;%lu;%lu;%lum"
@@ -68,6 +71,11 @@ nnoremap <Leader>b :buffers<CR>:buffer<Space>
 set splitbelow
 set splitright
 
+function! GitStatus()
+  let [a,m,r] = GitGutterGetHunkSummary()
+  return printf('%s +%d ~%d -%d', FugitiveHead(), a, m, r)
+endfunction
+
 let g:netrw_list_hide= '\(^\|\s\s\)\zs\.\S\+'
 
 let g:python_highlight_all = 1
@@ -91,13 +99,13 @@ let g:lightline.component_type = {
                         \ }
 
 let g:lightline.component_function = {
-                        \ 'gitbranch': 'FugitiveHead'
+                        \ 'gitstatus': 'GitStatus'
                         \ }
 
 
 let g:lightline.active = {
                         \ 'left': [ [ 'mode', 'paste' ],
-                        \           [ 'gitbranch', 'readonly', 'filename', 'modified' ] ],
+                        \           [ 'gitstatus', 'readonly', 'filename', 'modified' ] ],
                         \ 'right': [ [ 'linter_checking', 'linter_errors', 'linter_warnings', 'linter_infos', 'linter_ok', 'lineinfo' ],
                         \            [ 'percent' ],
                         \            [ 'fileformat', 'fileencoding', 'filetype' ] ]