Intorduce "config edit-ini" sub command to help maintaining INI config file (#35735)

Ref: #32669. Helps addressing
https://gitea.com/gitea/helm-chart/issues/356.

cmd/main.go

@@ -128,6 +128,7 @@ func NewMainApp(appVer AppVersion) *cli.Command {
 
 	// these sub-commands do not need the config file, and they do not depend on any path or environment variable.
 	subCmdStandalone := []*cli.Command{
+		cmdConfig(),
 		cmdCert(),
 		CmdGenerate,
 		CmdDocs,