feat(format): add :lang zig formatter

modules/lang/zig/config.el

@@ -11,6 +11,7 @@
   :hook (zig-mode . rainbow-delimiters-mode)
   :config
   (setq zig-format-on-save nil) ; rely on :editor format instead
+  (set-formatter! 'zigfmt '("zig" "fmt" "--stdin") :modes '(zig-mode))
 
   (when (modulep! +lsp)
     (add-hook 'zig-mode-local-vars-hook #'lsp! 'append))

modules/lang/zig/doctor.el

@@ -10,7 +10,10 @@
          "This module requires (:tools tree-sitter)")
 
 (unless (executable-find "zig")
-  (warn! "Couldn't find zig binary"))
+  (warn! "Couldn't find zig binary")
+
+  (when (modulep! :editor format)
+    (warn! "Formatting will be disabled")))
 
 (when (modulep! +lsp)
   (unless (executable-find "zls")