chg: dev: added idea in TODO comment !minor

bin/compose

@@ -31,6 +31,9 @@
 ## - some relations are configured in compose.yml but should not trigger the loading
 ##   of necessary component (for instance, apache --> log-rotate), if log-rotate is
 ##   not there, this link should considered optional.
+## - Could probably allow an unexistent charm to be populated with only "docker-image:"
+##   of the same name. Although this should trigger a visible warning.
+
 
 #:-
 [ -e /etc/shlib ] && . /etc/shlib || {