file-based program document enhancement (#49928)

* update System.CommandLine usage and mention env dotnet shebang config

* update file-based-programs.md

* apply copilot suggestions

Author: WeihanLi

docs/csharp/fundamentals/tutorials/file-based-programs.md

@@ -84,7 +84,13 @@ On unix, you can run file-based apps directly, typing the source file name on th
    #!/usr/local/share/dotnet/dotnet run
    ```
 
-The location of `dotnet` can be different on different unix installations. Use the command `whence dotnet` to local the `dotnet` host in your environment.
+The location of `dotnet` can be different on different unix installations. Use the command `which dotnet` to locate the `dotnet` host in your environment.
+
+Alternatively, you can use #!/usr/bin/env dotnet to resolve the dotnet path from the PATH environment variable automatically:
+
+```csharp
+#!/usr/bin/env dotnet
+```
 
 After making these two changes, you can run the program from the command line directly:
 
@@ -211,7 +217,7 @@ The `System.CommandLine` library offers several key benefits:
    :::code language="csharp" source="./snippets/file-based-programs/AsciiArt.cs" id="CommandLinePackage":::
 
    > [!IMPORTANT]
-   > The version `2.0.0-beta6` was the latest version when this tutorial was last updated. If there's a newer version available, use the latest version to ensure you have the latest security packages. Check the package's [NuGet page](https://www.nuget.org/packages/System.CommandLine) for the latest version to ensure you use a package version with the latest security fixes.
+   > The version `2.0.0` was the latest version when this tutorial was last updated. If there's a newer version available, use the latest version to ensure you have the latest security packages. Check the package's [NuGet page](https://www.nuget.org/packages/System.CommandLine) for the latest version to ensure you use a package version with the latest security fixes.
 
 1. Add the necessary using statements at the top of your file (after the `#!` and `#:package` directives):
 

docs/csharp/fundamentals/tutorials/snippets/file-based-programs/AsciiArt

@@ -1,7 +1,7 @@
 #!/usr/local/share/dotnet/dotnet run
 
 #:package Colorful.Console@1.2.15
-#:package System.CommandLine@2.0.0-beta6
+#:package System.CommandLine@2.0.0
 
 using System.CommandLine;
 using System.CommandLine.Parsing;

docs/csharp/fundamentals/tutorials/snippets/file-based-programs/AsciiArt.cs

@@ -4,7 +4,7 @@
 #:package Colorful.Console@1.2.15
 // </ColorfulPackage>
 // <CommandLinePackage>
-#:package System.CommandLine@2.0.0-beta6
+#:package System.CommandLine@2.0.0
 // </CommandLinePackage>
 
 // <Usings>