portage/README.md: You can mount volumes from stopped containers

As Sven Dowideit describes in a pending doc update [1].

[1]: https://github.com/dotcloud/docker/pull/3389

diff --git a/portage/README.md b/portage/README.md
index 534124ace4028ed64b4184cccf4b783b43175bc9..43a5bc90734483c9c3a1cfcb6bd39a169d9a375e 100644 (file)
--- a/portage/README.md
+++ b/portage/README.md
@@ -44,5 +44,13 @@ will still be local to your client containers, so you'll get
 promptings for reading the news on both `d1a49abc4b3c` and
 `187adaf8babd`.
 
+You can use container volumes even if their container is not running.
+For example:
+
+    $ docker run -name portage wking/portage true
+
+However, it may be useful to leave the container running so you don't
+remove it up by accident.
+
 [VOLUME]: http://docs.docker.io/en/latest/use/builder/#volume
 [volumes-from]: http://docs.docker.io/en/latest/use/working_with_volumes/#mount-volumes-from-an-existing-container