Allow --services in config

Signed-off-by: Muz <git@mustaqila.li>

podman_compose.py

@@ -2282,7 +2282,10 @@ def compose_logs(compose, args):
 
 
 @cmd_run(podman_compose, "config", "displays the compose file")
-def compose_config(compose, args):  # pylint: disable=unused-argument
+def compose_config(compose, args):
+    if args.services:
+        for service in compose.services: print(service)
+        return
     print(compose.merged_yaml)
 
 
@@ -2663,6 +2666,15 @@ def compose_build_parse(parser):
     )
 
 
+@cmd_parse(podman_compose, "config")
+def compose_config_parse(parser):
+    parser.add_argument(
+        "--services",
+        help="Print the service names, one per line.",
+        action="store_true"
+    )
+
+
 def main():
     podman_compose.run()