Update option usage

Signed-off-by: xaxys <[email protected]>

README.md

@@ -32,7 +32,7 @@ bubbler [options] <input file>
 - `-single`: Generate Single File (Combine all definitions into one file, instead of one generated file per source file)
 - `-minimal`: Generate Minimal Code (Usually without default getter/setter methods)
 - `-decnum`: Force Generate Decimal Format for Constant Value (Translate `0xFF` to `255`, `0b1111` to `15`, etc.)
-- `-signext`: Sign Extension Method used for Integer Field (Options: `shift`, `arith`)
+- `-signext <method>`: Sign Extension Method used for Integer Field (Options: `shift`, `arith`)
 
 ### Examples
 

README_cn.md

@@ -32,7 +32,7 @@ bubbler [options] <input file>
 - `-single`: 生成单个文件（将所有定义合并到一个文件中，而不是每个源文件生成一个文件）
 - `-minimal`: 生成最小代码（通常不包含默认的getter/setter方法）
 - `-decnum`: 强制生成十进制格式的常量值（将 `0xFF` 翻译为 `255`, `0b1111` 翻译为 `15` 等）
-- `-signext`: 用于整数字段的符号扩展方法（选项: `shift`, `arith`）
+- `-signext <method>`: 用于整数字段的符号扩展方法（选项: `shift`, `arith`）
 
 ### 示例
 

main.go

@@ -39,21 +39,21 @@ Usage:
   bubbler [options] <input file>
 
 Options:
-  -t <target>  Target Language
-  -o <output>  Output Path
-  -inner       Generate Inner Class
-  -single      Generate Single File
-  -minimal     Generate Minimal Code
-  -decnum      Force Generate Decimal Format for Constant Value
-  -signext     Sign Extension Method (shift, arith)
+  -t <target>        Target Language
+  -o <output>        Output Path
+  -inner             Generate Inner Class
+  -single            Generate Single File
+  -minimal           Generate Minimal Code
+  -decnum            Force Generate Decimal Format for Constant Value
+  -signext <method>  Sign Extension Method (shift, arith)
 
 Targets:
 {{ range .Generators }}  {{ . }}
 {{ end }}
 Examples:
   bubbler -t c -minimal -o output/ example.bb
   bubbler -t c -single -o gen.hpp example.bb
-  bubbler -t py -decnum -signext=arith -o output example.bb
+  bubbler -t py -decnum -signext arith -o output example.bb
 
 For more information, please visit: https://github.com/xaxys/bubbler
 {{ end }}