Docs: correct the description of docker cp

Signed-off-by: Lei Jitang <leijitang@huawei.com>

contrib/completion/fish/docker.fish

@@ -109,7 +109,7 @@ complete -c docker -A -f -n '__fish_seen_subcommand_from commit' -s p -l pause -
 complete -c docker -A -f -n '__fish_seen_subcommand_from commit' -a '(__fish_print_docker_containers all)' -d "Container"
 
 # cp
-complete -c docker -f -n '__fish_docker_no_subcommand' -a cp -d "Copy files/folders from a container's filesystem to the host path"
+complete -c docker -f -n '__fish_docker_no_subcommand' -a cp -d "Copy files/folders between a container and the local filesystem"
 complete -c docker -A -f -n '__fish_seen_subcommand_from cp' -l help -d 'Print usage'
 
 # create

docker/flags.go

@@ -24,7 +24,7 @@ var dockerCommands = []command{
 	{"attach", "Attach to a running container"},
 	{"build", "Build an image from a Dockerfile"},
 	{"commit", "Create a new image from a container's changes"},
-	{"cp", "Copy files/folders from a container to a HOSTDIR or to STDOUT"},
+	{"cp", "Copy files/folders between a container and the local filesystem"},
 	{"create", "Create a new container"},
 	{"diff", "Inspect changes on a container's filesystem"},
 	{"events", "Get real time events from the server"},

man/docker.1.md

@@ -184,7 +184,7 @@ unix://[/path/to/socket] to use.
   See **docker-commit(1)** for full documentation on the **commit** command.
 
 **cp**
-  Copy files/folders from a container's filesystem to the host
+  Copy files/folders between a container and the local filesystem
   See **docker-cp(1)** for full documentation on the **cp** command.
 
 **create**