update docs about ram only redis

README_ES.md

@@ -91,9 +91,11 @@ version: '3.8'
 services:
   redis:
     image: redis:7-alpine
-    # Set a size limit. See link below on how to customise.
+    # This is required to stay in RAM only.
+    command: redis-server --save "" --appendonly no
+    # Additionally, you can set a size limit. See link below on how to customise.
     # https://redis.io/docs/manual/eviction/
-    # command: redis-server --maxmemory 1gb --maxmemory-policy allkeys-lru
+    # --maxmemory 1gb --maxmemory-policy allkeys-lru
 
   app:
     image: cupcakearmy/cryptgeon:latest