update readme & adjust eg with parse error type check

Author: hellflame

README.md

@@ -82,7 +82,7 @@ About object __parser__ :
 
 1. `NewParser` first argument is the name of your program, but it's ok __not to fill__ , when it's empty string, program name will be `os.Args[0]` , which can be wired when using `go run`, but it will be the executable file's name when you release the code(using `go build`). It can be convinient where the release name is uncertain
 2. `help` function is auto injected, but you can disable it when using `NewParser`, with `&ParserConfig{DisableHelp: true}`. then you can use any way to define the `help` function, or whether to `help` 
-3. When `help` showed up, the program will default __exit with code 1__ , this is stoppable by setting `ParserConfig.ContinueOnHelp`  to be `true`, you can use your own help function instead
+3. When `help` showed up, the program will default __exit with code 1 (version < v1.5.0)__ or __return error type BreakAfterHelp (version >= 1.5.0)__ , this is stoppable by setting `ParserConfig.ContinueOnHelp`  to be `true`, you can use your own help function instead
 
 About __parse__ action:
 

docs/cn.md

@@ -76,7 +76,7 @@ hello hellflame
 
 1. `NewParser` 第一个参数是程序的名字, 但__可以为空__ , 如果程序名为空, 则会使用 `os.Args[0]` 作为程序名 , 只是用 `go run` 时会有点怪怪的，但当发布为可执行文件，在运行时就会是可执行文件的名字(通过 `go build` 生成)，所以在发布名称不确定的时候会比较方便
 2. `help` 方法会自动注入, 但也可以在 `NewParser` 时设定 `&ParserConfig{DisableHelp: true}` 来取消这个帮助入口，然后就可以用自己的帮助函数，甚至不给出帮助函数
-3. 帮助信息显示后，程序会以状态码 1 退出程序。可以设置 `ParserConfig.ContinueOnHelp`  为 `true`, 阻止这种退出
+3. 帮助信息显示后，程序会以状态码 1 退出程序(verison < v1.5.0)，或者返回错误类型 `BreakAfterHelp` (version >= 1.5.0)。可以设置 `ParserConfig.ContinueOnHelp`  为 `true`, 阻止这种退出
 
 关于 __parse__ 动作执行:
 

examples/shell-completion/main.go

@@ -7,6 +7,7 @@ package main
 import (
 	"fmt"
 	"github.com/hellflame/argparse"
+	"os"
 )
 
 func main() {
@@ -21,7 +22,13 @@ func main() {
 	install := p.AddCommand("install", "", nil)
 	install.Strings("i", "in", nil)
 	if e := p.Parse(nil); e != nil {
-		fmt.Println(e.Error())
+		switch e.(type) {
+		case argparse.BreakAfterHelp:
+			os.Exit(1)
+		case argparse.BreakAfterShellScript:
+		default:
+			fmt.Printf(e.Error())
+		}
 		return
 	}
 }