Update README.md

Author: alekswebnet

README.md

@@ -8,6 +8,7 @@ A web component for viewing pdf files in the browser. The package is based on [P
 
 [![npm version](https://img.shields.io/npm/v/pdfjs-viewer-element?logo=npm&logoColor=fff)](https://www.npmjs.com/package/pdfjs-viewer-element)
 [![Package Quality](https://packagequality.com/shield/pdfjs-viewer-element.svg)](https://packagequality.com/#?package=pdfjs-viewer-element)
+[![Published on webcomponents.org](https://img.shields.io/badge/webcomponents.org-published-blue.svg)](https://www.webcomponents.org/element/pdfjs-viewer-element)
 
 ## Docs