Add vim headers to Dockerfile

Sometimes I have to use nano to get the tabs right because it is different than my local
settings. Remove the tab pain from some users. @tianon don't kill me, wanted to see if 
I could get away with this. If so, I could do them all... (shell scripts)? Or should we just forget it?

shouldn't this be `set noexpandtab` ?

Also, wouldn't these be less disruptive at the end of the file instead of the beginning?