Needed to maintain listing in k6 Extensions Registry

[javaducky]

We've recently updated the requirements for maintaining an extension within the listing on our site. As such, please address the following items to maintain your listing within the registry:

• add the xk6 topic to your repository metadata
• add an examples directory containing k6 test scripts making use of your extension
• needs to build with a recent version of k6; minimum v0.43

For more information on these and other listing requirements, please take a look at the registry requirements.