Update port.rb Documentation

[nvtkaszpir]

fix comment section, expand example section

[chef-supermarket]

Hi. I am an automated pull request bot named Curry. There are commits in this pull request whose authors are not yet authorized to contribute to Chef Software, Inc. projects or are using a non-GitHub verified email address. To become authorized to contribute, you will need to sign the Contributor License Agreement (CLA) as an individual or on behalf of your company. You can read more on Chef's blog.

GitHub Users Who Are Not Authorized To Contribute

The following GitHub users do not appear to have signed a CLA:

• @nvtkaszpir

Please sign the CLA here.

[chris-rock]

Since we are at it, lets remove the usage comment, since everything is covered within the example block

[chris-rock]

@nvtkaszpir Thanks for fixing that. Please do not forget to sign the CLA

[chef-supermarket]

Hi. Your friendly Curry bot here. Just letting you know that all commit authors have become authorized to contribute. I have added the "Signed CLA" label to this issue so it can easily be found in the future.

[chris-rock]

Thanks a lot for the improvement @nvtkaszpir