Add sponsor

README.md

@@ -2,6 +2,9 @@
 
 A collective list of free APIs for use in software and web development.
 
+Sponsor:
+<a href="https://ultimatecourses.com?utm_source=github.com"><img src="https://ultimatecourses.com/assets/img/banners/uc-leader.svg" style="width:100%;max-width:100%"></a>
+
 A public API for this project can be found [here](https://github.com/davemachado/public-api) - thanks to [DigitalOcean](https://www.digitalocean.com/) for helping us provide this service!
 
 For information on contributing to this project, please see the [contributing guide](.github/CONTRIBUTING.md).