[css-forms-1] Properties inherited from fieldset to anonymous content box

[kbabbitt]

In the HTML spec, there's a list of CSS properties that are supposed to inherit from a <fieldset> element to its child anonymous content box.

In whatwg/html#11095 I proposed changing this list to include the properties from Gaps 1. In the discussion it was suggested that this list of properties be maintained in a CSS specification rather than HTML.

Forms seems to me like a natural home for this list, so I'd like to propose moving it there.

[annevk]

The only potential downside I see with forms is that a lot of its contents will be eventually subsumed by other documents, e.g., HTML's rendering section. But for this it's certainly better than HTML.