Consider marking up editors so tools can aggregate them

In https://lists.w3.org/Archives/Public/spec-prod/2021AprJun/0026.html we're looking at ways to find all the editors working on the web platform. I see that ecmarkup specs can include a list of contributors (https://github.com/tc39/proposal-atomics-wait-async/blob/a641110639807e6a37c2f86827805697c5768237/spec.html#L12, https://github.com/tc39/proposal-class-static-block/blob/7de25839a5671dc1761fc8afb25a616209c12413/spec/index.html#L8), which get propagated to a block at the bottom of the specification.

The list of contributors there isn't annotated in a way that a program can find it. If you look at https://drafts.csswg.org/css-regions/ or https://w3c.github.io/media-source/, you can see how these specs mark up their editors using h-card:

<dd class="p-author h-card vcard"><span class="p-name fn">Jerry Smith</span>
            (<a class="p-org org h-org h-card" href="http://www.microsoft.com/">Microsoft Corporation</a>)
           (Until September 2017)</dd>

In particular, the parsing in https://github.com/w3c/reffy/pull/593 uses the h-card, p-name, and p-org classes to identify the relevant parts of an editor, and it might make sense to use p-author in order to be a bit more independent of the <dl> structure that w3c-ish specs use.

The issue names ecmarkup contributor lists, the linked example spec.html and spec/index.html files, and reffy pull request #593. Compare their h-card, p-name, p-org, and p-author handling first; done means generated specifications expose editor information in markup that aggregation tools can reliably identify.