add configuration for c-ts-mode

since we're using treesit-auto, treesitter modes will be used, and
apparently c-ts-mode overrides c-mode, and thus the usual mode hooks
and settings aren't used and we must use the treesitter mode
equivalents.

kind of annoying and confusing, but whatever

emacs.d/lang-modes.el

@@ -43,3 +43,10 @@
 
 (use-package lua-mode
   :ensure t)
+
+(use-package c-ts-mode
+  :config
+  (setq-default c-ts-mode-indent-style 'linux)
+  (setq-default c-ts-mode-indent-offset tab-width))
+
+