docker: prometheus and grafana for development (#16649)

config.mk

@@ -5,7 +5,7 @@
 # Enable services to be run in docker.
 #
 # Possible options: mysql, postgres, minio, inbucket, openldap, dejavu,
-# keycloak and elasticsearch
+# keycloak, elasticsearch, prometheus, and grafana.
 #
 # Must be space separated names.
 #