clean up docker compose naming and volume specification

docker-compose.yml

@@ -21,13 +21,13 @@ services:
       - POSTGRES_PASSWORD=secret
       - POSTGRES_DB=miniflux
     volumes:
-      - miniflux-db:/var/lib/postgresql/data
+      - rss_miniflux-db:/var/lib/postgresql/data
     healthcheck:
       test: ["CMD", "pg_isready", "-U", "miniflux"]
       interval: 10s
       start_period: 30s
 
-  reddit_rss:
+  reddit:
     build:
       context: ./
       dockerfile: Dockerfile
@@ -41,4 +41,5 @@ services:
       - RSS_HOST
 
 volumes:
-  miniflux-db:
+  rss_miniflux-db:
+    external: true