Finish and tidy up the domintro section

[domenic]

The domintro section currently lists the properties only; it doesn't list the constructor or methods.

Also, the way the properties are listed is a bit strange; it makes them look like static properties: URLPattern.protocol. Instead they should look like instance properties: urlPattern.protocol.

See whatwg/meta#190, or probably just skip to whatwg/meta#190 (comment) for my summary of best practices that we're trying to converge the ecosystem on a bit.