Revert "chore: remove gitsigns"

This reverts commit 9fef541628.

init.lua

@@ -24,6 +24,7 @@ require('lazy').setup {
   require 'plugins.lsp',
   require 'plugins.formatting',
   require 'plugins.autocompletion',
+  require 'plugins.gitsigns',
   require 'plugins.indent-blankline',
   require 'plugins.render-markdown',
   require 'plugins.misc',