feat(gs/emacs): Install clang-format+

Change-Id: I3560932953718ab9324bc490488f39605f03ee5e
Reviewed-on: https://cl.tvl.fyi/c/depot/+/1264
Reviewed-by: glittershark <grfn@gws.fyi>
Tested-by: BuildkiteCI

users/glittershark/emacs.d/cpp.el

@@ -22,6 +22,10 @@
 
 (use-package! protobuf-mode)
 
+(use-package! clang-format+
+  :config
+  (add-hook 'c-mode-common-hook #'clang-format+-mode))
+
 (comment
  (setq
   lsp-clients-clangd-executable

users/glittershark/emacs.d/packages.el

@@ -158,3 +158,4 @@
 
 ;;; cpp
 (package! protobuf-mode)
+(package! clang-format+)