docs: Add -s option

Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>

Documentation/crtools.txt

@@ -11,7 +11,7 @@ crtools - checkpoint/restore in userspace
 
 SYNOPSIS
 --------
-'crtools' [-c] [-f <file>] [-d] [-n] [-o <path>] [-D <path>] [-v [num]] [--help] <command> (-p|-t) <pid>
+'crtools' [-c] [-s] [-f <file>] [-d] [-n] [-o <path>] [-D <path>] [-v [num]] [--help] <command> (-p|-t) <pid>
 
 DESCRIPTION
 -----------
@@ -40,6 +40,9 @@ OPTIONS
     Use path 'path' as a base directory where to look for dump files set. This
     commands allpies to any <command>.
 
+-s::
+    Leave tasks in stopped state after checkpoint instead of killing them.
+
 -f <file>::
     This option is valid for 'show' command only and allows to see content of
     the <file> specified.