fix: Types w/ module augmentation

[rschristian]

Apparently module augmentation affects how consumers within node_modules get augmented types, as the following in user code wouldn't work:

declare module "preact" {
    interface HeadingHTMLAttributes {
        foo?: string;
    }
}

As jsx.d.ts imports from dom.d.ts, the snippet above wouldn't augment that interface and so the JSX types would remain unchanged for the user; instead, jsx.d.ts needs to import everything from the preact namespace directly to ensure users can overwrite/extend easily.

[coveralls]

coverage: 99.536%. remained the same
when pulling 25a05c9 on types/fix-module-agumentation
into c242faf on main.