Docs: fix README.md by adding setup for cmp-git (#1914)

README.md

@@ -93,14 +93,16 @@ lua <<EOF
     })
   })
 
+  -- To use git you need to install the plugin petertriho/cmp-git and uncomment lines below
   -- Set configuration for specific filetype.
-  cmp.setup.filetype('gitcommit', {
+  --[[ cmp.setup.filetype('gitcommit', {
     sources = cmp.config.sources({
-      { name = 'git' }, -- You can specify the `git` source if [you were installed it](https://github.com/petertriho/cmp-git).
+      { name = 'git' },
     }, {
       { name = 'buffer' },
     })
-  })
+ })
+ require("cmp_git").setup() ]]-- 
 
   -- Use buffer source for `/` and `?` (if you enabled `native_menu`, this won't work anymore).
   cmp.setup.cmdline({ '/', '?' }, {