Add docker registry URL to image name

Using fully qualified image names means
podman also works as an alternative to
docker. Docker implicitly pulls unqualified
images from docker.io, while podman requires
fully qualified image names by default.

docker/soarca/docker-compose.yml

@@ -1,7 +1,7 @@
 version: '3.7'
 services:
   mongodb_container:
-    image: mongo:latest
+    image: docker.io/mongo:latest
     container_name: mongo_soarca_stack
     environment:
       MONGO_INITDB_ROOT_USERNAME: "root"
@@ -14,7 +14,7 @@ services:
         target: /data/db
 
   mosquitto:
-    image: eclipse-mosquitto
+    image: docker.io/eclipse-mosquitto
     container_name: mosquitto
     volumes:
       - type: volume
@@ -39,7 +39,7 @@ services:
         mode: host
 
   soarca:
-    image: cossas/soarca:latest
+    image: docker.io/cossas/soarca:latest
     container_name: soarca_server
     environment:
       PORT: 8080