nit(tree-sitter): add rationale for debug mode var

modules/tools/tree-sitter/config.el

@@ -6,7 +6,10 @@
   :hook (tree-sitter-after-on . tree-sitter-hl-mode)
   :config
   (require 'tree-sitter-langs)
+
+  ;; This makes every node a link to a section of code
   (setq tree-sitter-debug-jump-buttons t
+        ;; and this highlights the entire sub tree in your code
         tree-sitter-debug-highlight-jump-region t)
 
   (defadvice! doom-tree-sitter-fail-gracefully-a (orig-fn &rest args)