Fixing a door edge scratch?

[Revsson]

Okay, so my buddy and I ran some power wires from the battery through
the firewall as suggested in some other DIY. My parking spot is next to a
concrete wall. I thought I had parked far enough way, but when my buddy
opened the door all the way, he scrapped the edge of the door on the wall.
Needless to say, I was NOT happy!!! Sure wish I would have thought to
have a piece of foam over there, just in case.

How do I go about fixing this scratch? I should probably take a pic and/or
measure how big it is. It might not be a big deal to some, but knowing it
is there for future rust(?) is going to bother me. What can person with no
painting experience do to fix this? Would touch up paint be the route?
Or just wax over it as best I can, and keep and eye on it? Obviously, those
door edge protectors would detract from the smooth look of the side, right?