Improve ForEachService description

Co-authored-by: Milas Bowman <[email protected]>

types/project.go

@@ -188,8 +188,9 @@ func (p *Project) AllServices() Services {
 
 type ServiceFunc func(name string, service *ServiceConfig) error
 
-// ForEachService runs ServiceFunc on each service and dependencies according to DependencyPolicy
-// The fn ServiceFunc should not mutate its ServiceConfig attribute
+// ForEachService runs ServiceFunc on each service and dependencies according to DependencyPolicy.
+//
+// No copies are created; any mutation of `*ServiceConfig` by the fn `ServiceFunc` will apply to this `*Project` object.
 func (p *Project) ForEachService(names []string, fn ServiceFunc, options ...DependencyOption) error {
 	if len(options) == 0 {
 		// backward compatibility