Add funding

Author: alekswebnet

.github/FUNDING.yml

@@ -0,0 +1 @@
+open_collective: oleksandr-shevchuk

README.md

@@ -35,6 +35,10 @@ Then specify the path to the directory with the `viewer-path` property (`/pdfjs`
 [![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)
 
+# Support project
+
+[![Backers on Open Collective](https://opencollective.com/yourprojectname/backers/badge.svg)](https://opencollective.com/oleksandr-shevchuk)
+
 ## Docs
 
 [Getting started](https://alekswebnet.github.io/pdfjs-viewer-element/)