Override indent-tabs-mode for Makefiles

Author: Matthias Koeppe

.dir-locals.el

@@ -3,4 +3,7 @@
 
 ((nil
   ;; Use space instead of tabs for indentation
-  (indent-tabs-mode . nil)))
+  (indent-tabs-mode . nil))
+ (makefile-mode
+  ;; But use tabs in Makefiles
+  (indent-tabs-mode . t)))