~/.bin/rt: Add a file-comment.

.bin/rt

#!/bin/bash
# rt - A repository tool abstracting away from any specific VCS.
#
# Currently supported: git, hg.
if [ $# -lt 1 ]; then
	echo "Usage: $0 <cmd> <repo> [<args>]"
	echo "  executes <cmd> for <repo> (passing <args> through)"