Include repository in docker image

Motivation:

The docker-compose image does not work under Debian systems because such
systems disable automatically resolving.  This is done because it is
unsafe: you might download the "wrong" image.

Modification:

Update the reference so that it includes the registry (dockerhub.io)
explicitly.

Result:

Docker compose now works under Debian

docker-compose.dev.yaml

@@ -1,6 +1,6 @@
 services:
   mongodb:
-    image: bitnami/mongodb:4.2
+    image: docker.io/bitnami/mongodb:4.2
     volumes:
       - mongodb_data:/bitnami
   backend: