Fix #62 Add link to Docker volumes doc
diff --git a/README.md b/README.md
index 0ded947..02c0f59 100644
--- a/README.md
+++ b/README.md
@@ -41,9 +41,11 @@
This is highly recommended. Treat the jenkins_home directory as you would a database - in Docker you would generally put a database on a volume.
-If your volume is inside a container - you can use ```docker cp $ID:/var/jenkins_home``` command to extract the data.
+If your volume is inside a container - you can use ```docker cp $ID:/var/jenkins_home``` command to extract the data, or other options to find where the volume data is.
Note that some symlinks on some OSes may be converted to copies (this can confuse jenkins with lastStableBuild links etc)
+For more info check Docker docs section on [Managing data in containers](https://docs.docker.com/userguide/dockervolumes/)
+
# Setting the number of executors
You can specify and set the number of executors of your Jenkins master instance using a groovy script. By default its set to 2 executors, but you can extend the image and change it to your desired number of executors :