Added blog link

Added link to blog article about docker_get_data_volume_info.sh

README.md

@@ -19,3 +19,5 @@ data volume the current size of the data volume and a list of stopped or running
 that have a link to this data volume, including the image corresponding to the container.
 The script allows me to easily see if there are some data volumes on my disk that are taking
 up a lot of space and are not needed anymore.
+
+You can find more details in my blog post [Listing information for all your named/unnamed data volumes](https://www.guidodiepen.nl/2017/04/listing-information-for-all-your-named-unnamed-data-volumes/)