Update README.md

Example of Catch-All parameters.

README.md

@@ -85,13 +85,15 @@ func main() {
 func main() {
 	r := gin.Default()
 	
+	// This handler will match /user/john but will not match neither /user/ or /user
 	r.GET("/user/:name", func(c *gin.Context) {
 		name := c.Params.ByName("name")
 		message := "Hello "+name
 		c.String(200, message)
 	})
 
-	r.GET("/user/:name/:action", func(c *gin.Context) {
+	// However, this one will match /user/john and also /user/john/send
+	r.GET("/user/:name/*action", func(c *gin.Context) {
 		name := c.Params.ByName("name")
 		action := c.Params.ByName("action")
 		message := name + " is " + action