add named volumes to couchdb and elasticsearch

deleted by 71c1cc2, but docker still needs those volumes to save its
service data somewhere on the host, otherwise it will recreate dbs at
every container restart

docker-compose.yml

@@ -8,6 +8,7 @@ services:
       COUCHDB_USER: "yourcouchdbusername"
       COUCHDB_PASSWORD: "yourcouchdbpassword"
     volumes:
+      - 'couchdb:/opt/couchdb/data'
       - './configs:/opt/couchdb/etc/local.d'
     tty: true
   elasticsearch:
@@ -18,6 +19,8 @@ services:
       # See https://www.elastic.co/guide/en/elasticsearch/reference/7.16/docker.html
       - 'discovery.type=single-node'
       - 'ES_JAVA_OPTS=-Xms1g -Xmx1g'
+    volumes:
+      - 'elasticsearch:/usr/share/elasticsearch/data'
     ports :
       - '127.0.0.1:9200:9200'
 volumes: