accept discord token as env

we only really need that to function anyway, other things like jellyfin will
just not do anything and we have default value for avatar reset.

docker-compose.yml.default

@@ -2,5 +2,11 @@ services:
   bot:
     restart: unless-stopped
     build: .
-    volumes:
-      - ./config.json:/app/config.json
+    environment:
+      - DISCORD=TOKEN_HERE
+#    volumes:
+#    Uncomment the config for advanced configuration like Jellyfin.
+#      - ./config.json:/app/config.json
+#    Uncomment avatars for an avatars folder it can rotate through.
+#      - ./avatars:/app/avatars
+