Provide examples of API usage in https://docs.webxdc.org/spec.html

[link2xt]

Especially for sendUpdate and setUpdateListener.

[WofWca]

Hmm good point. Wouldn't an example app suffice though? Or I guess you'd want to see an example beside the spec of the API.

[link2xt]

Examples are already provided for sendToChat and importFiles. sendUpdate and setUpdateListener are arguably more important, so they need inline examples too.