add man page

[haircommander]

conmon could use a man page. while it's not really intended to be called by the end user, other documentation often references to it, like discussed here

[TomSweeneyRedHat]

@mheon @baude can you comment on what you'd like to see (or not see) in this man page? I know you'd some concerns/thoughts in the standup and I want to make sure they're covered here. I think the main issue was to discourage people from using conmon directly, that its sole design was for use with Podman. Any other use should not be supportable.

[mheon]

We should not go into details on arguments and use, IMO. Manpage should make it clear that we do not intend that this be called directly, only by Podman and CRI-O, and that it has been tuned exclusively for those uses.

[pwFoo]

Would be nice to know how to use conman. Maybe would be nice for minimal setup of runc / crun direktly with conman

[rhatdan]

Conmon has a man page now. If you want more information on the man page or advanced howtos. PRs welcome. :^)