Changes

* <ol> <li>HTML Living Standard, Web Worker sectionWorkers: https://html.spec.whatwg.org/multipage/workers.html. Last updated: 2 Dec. 2020.</li>* <li>MDN Web Docs, Using Web WorkersWorker API: https://developer.mozilla.org/en-US/docs/Web/API/Web_Workers_API. Last updated: 26 Aug. 2020.</li></Using_web_workersol>