added sponsor to readme

Author: chriskacerguis

README.md

@@ -237,3 +237,9 @@ Pull Requests are the best way to fix bugs or add features. I know loads of you
 contribute if you have improvements to be made and I'll keep releasing versions over time.
 
 [![GitHub license](https://img.shields.io/badge/license-MIT-blue.svg?style=flat-square)](https://raw.githubusercontent.com/chriskacerguis/codeigniter-restserver/master/LICENSE)
+
+## Sponsor
+
+<a target='_blank' rel='nofollow' href='https://app.codesponsor.io/link/x5iG9vGhiu6Mb29mcC1SmhnF/chriskacerguis/codeigniter-restserver'>
+  <img alt='Sponsor' width='888' height='68' src='https://app.codesponsor.io/embed/x5iG9vGhiu6Mb29mcC1SmhnF/chriskacerguis/codeigniter-restserver.svg' />
+</a>