feat(navigation): Add config for centaur-tabs, not loaded on startup

As I don't see myself using tabs all the time, but potentially wanting
access to them every now and then, I need to manually trigger one of the
tab / tab-group switching keybindings, or M-x centaur-tabs-mode to load
and enable it.

core/siren-core-modules.el

@@ -48,6 +48,7 @@
 ;; Navigation
 (require 'siren-anzu)
 (require 'siren-avy)
+(require 'siren-centaur-tabs)
 (require 'siren-dired)
 (require 'siren-direx)
 (require 'siren-dumb-jump)

modules/navigation/siren-centaur-tabs.el

@@ -0,0 +1,33 @@
+;;; siren-centaur-tabs.el --- jimeh's Emacs Siren: centaur-tabs configuration.
+
+;;; Commentary:
+
+;; Basic configuration for centaur-tabs.
+
+;;; Code:
+
+(use-package centaur-tabs
+  :commands centaur-tabs-mode
+
+  :bind
+  ("s-[" . centaur-tabs-backward-tab)
+  ("s-]" . centaur-tabs-forward-tab)
+  ("s-<" . centaur-tabs-backward-group)
+  ("s->" . centaur-tabs-forward-group)
+
+  :custom
+  (centaur-tabs-height 32)
+  (centaur-tabs-modified-marker "•") ;; Unicode Bullet (0x2022)
+  (centaur-tabs-set-bar 'left)
+  (centaur-tabs-set-icons t)
+  (centaur-tabs-set-modified-marker t)
+  (centaur-tabs-show-navigation-buttons nil)
+  (centaur-tabs-style "bar")
+
+  :config
+  (centaur-tabs-mode t)
+  (centaur-tabs-headline-match)
+  (centaur-tabs-group-by-projectile-project))
+
+(provide 'siren-centaur-tabs)
+;;; siren-centaur-tabs.el ends here