Update README.md: add backers and sponsor (#907)

Author: vharseko

README.md

@@ -91,5 +91,20 @@ The next step is then to go to [http://login.domain.com:8080/openam](http://logi
 Please, make [Pull request](https://github.com/OpenIdentityPlatform/OpenAM/pulls)
 
 <a href="https://github.com/OpenIdentityPlatform/OpenAM/graphs/contributors">
-  <img src="https://contributors-img.web.app/image?repo=OpenIdentityPlatform/OpenAM" />
+  <!--img src="https://contributors-img.web.app/image?repo=OpenIdentityPlatform/OpenAM" /-->
+  <img src="https://opencollective.com/OpenAM/contributors.svg?width=890&button=false" />
 </a>
+
+## Backers
+Thank you to all our backers! 🙏 [Become a backer](https://opencollective.com/OpenAM#backer)
+
+<a href="https://opencollective.com/OpenAM#backers" target="_blank">
+ <img src="https://opencollective.com/OpenAM/backers.svg?width=890">
+</a>
+
+## Sponsors
+Support this project by becoming a sponsor. Your logo will show up here with a link to your website. [Become a sponsor](https://opencollective.com/OpenAM#sponsor)
+
+<a href="https://opencollective.com/OpenAM/sponsor/0/website" target="_blank">
+ <img src="https://opencollective.com/OpenAM/sponsor/0/avatar.svg">
+</a>