Add keybinding for quick ediff

contrapunctus/cp-fm.el

@@ -24,6 +24,7 @@
   :bind (("<f2> s"  . cp/sxiv)
          :map dired-mode-map
          ("W"       . wdired-change-to-wdired-mode)
+         ("e"       . #'cp/dired-do-ediff)
          ;; after learning that this copies whole paths with null
          ;; argument, this became a whole lot more useful
          ("C-w"     . dired-copy-filename-as-kill)
@@ -89,6 +90,8 @@ the files listed."
   ;;    start. Signal to the user that it is starting, and let them
   ;;    kill it if they want.
   ;; 5. Create variable to hold default arguments
+  ;; 6. What should be the behavior when we open Dired-marked files,
+  ;;    then mark files within sxiv?
 
   ;; BUG - doesn't work as intended with non '*' markers (e.g. C or D)