update go.mod of example

Author: hujun-open

example/go.mod

@@ -3,12 +3,15 @@ module cptool
 go 1.20
 
 require (
-	github.com/hujun-open/myflags v0.3.3
+	github.com/hujun-open/cobra v0.1.0
+	github.com/hujun-open/myflags/v2 v2.0.1
 
 )
 
 require (
+	github.com/cpuguy83/go-md2man/v2 v2.0.6 // indirect
+	github.com/hujun-open/pflag v0.2.0 // indirect
 	github.com/inconshreveable/mousetrap v1.1.0 // indirect
+	github.com/russross/blackfriday/v2 v2.1.0 // indirect
+	gopkg.in/yaml.v3 v3.0.1 // indirect
 )
-
-