cmd/puppeth: fix typos and review suggestions

cmd/puppeth/module_nginx.go

@@ -92,7 +92,7 @@ type nginxInfos struct {
 	port int
 }
 
-// Report converts the typed struct into a plain string->string map, cotnaining
+// Report converts the typed struct into a plain string->string map, containing
 // most - but not all - fields for reporting to the user.
 func (info *nginxInfos) Report() map[string]string {
 	return map[string]string{