TypeError: __init__() got an unexpected keyword argument 'debug'

Documentation on pypi and github says it should be instantiated like this:

```
SMTPServer(
self,
('0.0.0.0', 465),
None,
require_authentication=True,
ssl=True,
certfile='examples/server.crt',
keyfile='examples/server.key',
credential_validator=FakeCredentialValidator(),
debug=True
)
```

However it is not correct as constructor in recent release does not have debug parameter and it results in:

```
TypeError: __init__() got an unexpected keyword argument 'debug'
```

Please fix documentation or implement debugging and debug argument.

Compare the documented SMTPServer constructor example on PyPI and GitHub with the recent release's actual constructor. Decide whether the intended fix is to remove debug=True from the documentation or restore the debug argument, then verify that the example no longer raises the reported TypeError.

Written by the indexing model from the issue text.