Revise SDK customization documentation

[msyyc]

autorest.python repo is archived so we move the content here.

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[Copilot]

Pull request overview

Moves archived AutoRest Python customization guidance into this repository and adds TypeSpec-first recommendations.

Changes:

• Documents _patch.py customization workflows.
• Adds model, operation, client, and authentication examples.
• Removes obsolete postprocessing guidance.

Suppressed comments (2)

doc/dev/customize_code/how-to-patch-sdk-code.md:232

• Current generated clients use _client.py; _service_client.py is not generated, so this second documented layout also points to a nonexistent file.

        └───models

doc/dev/customize_code/how-to-patch-sdk-code.md:241

• Import the generated class from _client.py; as written, copying this example raises ModuleNotFoundError because _service_client.py is not part of the generated layout.

[Copilot]

Pull request overview

Copilot reviewed 1 out of 1 changed files in this pull request and generated no new comments.

Suppressed comments (3)

doc/dev/customize_code/how-to-patch-sdk-code.md:211

• The custom credential is part of the public ServiceClient signature, but omitting it from __all__ prevents the generated package initializer from exposing it. Readers following this example cannot import MyCredential from the package to construct the client.

__all__ = ["ServiceClient"]

doc/dev/customize_code/how-to-patch-sdk-code.md:248

• This factory accepts arbitrary client options in kwargs but silently discards them, so documented options such as transport, retry, or logging configuration have no effect when the factory is used. Forward kwargs to the client constructor.

        return cls(
            credential=AzureKeyCredential(parsed_connection_string.pop("accesskey")),
            endpoint=parsed_connection_string.pop("endpoint")
        )

doc/dev/customize_code/how-to-patch-sdk-code.md:148

• args is a tuple because it comes from *args, so calling append raises AttributeError whenever the keyword-only overload is used. Build a replacement tuple before forwarding the call.

        if not args:
            args.append({"foo": kwargs.pop("foo"), "bar": kwargs.pop("bar")})