Doom: Add undo-fu

evil-redo was refusing to work without it

doom/init.el

@@ -67,6 +67,7 @@
        electric          ; smarter, keyword-based electric-indent
        ;;ibuffer         ; interactive buffer management
        vc                ; version-control and Emacs, sitting in a tree
+       undo
 
        :term
        eshell            ; a consistent, cross-platform shell (WIP)