Renders the GeoCities style's marquee: the community feed crawling across
the page under the header, as a <marquee> did on a homepage of that era.
AppHeader renders it on every page. It draws nothing in any other style,
nor for a visitor, the feed being for signed-in users.
f
Marquee(): React.JSX.Element | null
Renders the marquee for a signed-in user in the GeoCities style, an empty band until the feed is loaded, so that the page under it doesn't move when it comes.
Usage
import * as mod from "src/components/layout/Marquee.tsx";