Man page improvements

[athulin]

The man page is unclear on if and how the -i and the [FILES]... alternatives interact. I suspect they don't, but the man page doesn't confirm that -- nor does it contradict it.

Without making any extensive tests, I suggest splitting the command line into two: one with the -i but without the [FILES]..., and one without -i but with [FILES].... to show what I assume is the intended usage. If not, please clarify man page accordingly: are any [FILES] added (conceptually) at the end of the -i list, or the other way around?

I also suggest correcting the minor confusion with [FILES]... : the three dots indicating repetition must be placed inside the brackets to be perfectly clear.