Wanna customize your fringe with Git markers similar to doom emacs? Add this to your init.el file:

(with-eval-after-load 'flycheck
  (setq flycheck-indication-mode 'right-fringe))
(with-eval-after-load 'git-gutter-fringe
  (fringe-helper-define 'git-gutter-fr:added '(center repeated) "XXX.....")
  (fringe-helper-define 'git-gutter-fr:modified '(center repeated) "XXX.....")
  (fringe-helper-define 'git-gutter-fr:deleted '(center repeated) "XXX....."))