Add instruction to run CouchDB with a mounted volume
Add instruction to run CouchDB with a mounted volume

closes #26

craig2017/docker-couchdb,mgk/docker-couchdb,thaihau/docker-couchdb,janl/docker-couchdb,bcoe/docker-couchdb,mappuji/rpi-couchdb,janl/docker-couchdb,apache/couchdb-docker