fix: handle StackName / Name correctly

pkg/config/app.go

@@ -43,13 +43,17 @@ type App struct {
 	Path   string
 }
 
-// StackName gets what the docker safe stack name is for the app
+// StackName gets what the docker safe stack name is for the app. This should
+// not not shown to the user, use a.Name for that. Give the output of this
+// command to Docker only.
 func (a App) StackName() string {
 	if _, exists := a.Env["STACK_NAME"]; exists {
 		return a.Env["STACK_NAME"]
 	}
+
 	stackName := SanitiseAppName(a.Name)
 	a.Env["STACK_NAME"] = stackName
+
 	return stackName
 }