@spectrum-web-components/icons-workflow/icons/sp-icon-rectangle.d.ts

Deliver [Spectrum Workflow Icons](https://spectrum.adobe.com/page/icons/) as either:

import { IconRectangle } from '../src/elements/IconRectangle.js';
declare global {
    interface HTMLElementTagNameMap {
        'sp-icon-rectangle': IconRectangle;
    }
}