Proposal: Add support for extended Schema

[bahrus]

Even if VSCode's lack of support for interplay between the HTML DOM and JavaScript means that there might be no pressing need to support events and properties (except for supporting JSX / tagged template literal libraries?), supporting an enhanced schema, as is being discussed here and being tested out here, as the default schema, would make editing such JSON files by hand easier.

Admittedly, there might not yet be a consensus on a single schema yet, so maybe this is a bit early.

[octref]

As I answered WICG/webcomponents#776 (comment), you need to define "support" before asking for "editor support". slots and events doesn't entail any editor support that can be easily done. If you just want to see them in auto-completion and hover, you can append those two to the end of the description field.