Update 'README.md'

README.md

@@ -1,19 +1,38 @@
 # typer
 
+命令行扩展，依赖click
+
+
 ## Usage
 
 ```
 
-app = typer.Typer(pretty_exceptions_enable=False)
+import typer
 
+app = typer.Typer()
 
-@cli.command()
-@typer_async
-async def account_payout_schedule() -> None:
-    pass
+@app.command()
+def greet(name: str):
+    """Greet the user by NAME."""
+    typer.echo(f"Hello, {name}!")
+
+@app.command()
+def add(a: int, b: int):
+    """Add two numbers."""
+    result = a + b
+    typer.echo(f"The sum of {a} and {b} is {result}.")
 
 if __name__ == "__main__":
-    cli()
-    
+    # 使用括号 () 调用一个对象时，实际上是在调用该对象的 __call__ 方法。这种设计允许对象表现得像函数
+    app()
+```
+
+命令行执行：
+```
+python script.py greet John
+python script.py add 1 3
+
 ```
 
+把第一个参数识别为命令，后面的识别为参数
+