Warn for unknown options

[kricsleo]

Describe the feature

Warn for unknown options could improve CLI usability and user experience.

For example, git (and others) warns about unknown options:

$ git -k
> unknown option: -k
> usage: git [-v | --version] [-h | --help] [-C <path>] [-c <name>=<value>]
>            [--exec-path[=<path>]] [--html-path] [--man-path] [--info-path]
>            [-p | --paginate | -P | --no-pager] [--no-replace-objects] [--no-lazy-fetch]
>            [--no-optional-locks] [--no-advice] [--bare] [--git-dir=<path>]
>            [--work-tree=<path>] [--namespace=<name>] [--config-env=<name>=<envvar>]
>            <command> [<args>]

Additional information

• Would you be willing to help implement this feature?