Update index.md (#995)

Add sponsor link at the bottom

Author: abaziz

docs/index.md

@@ -10,3 +10,17 @@ These are the key features of Reloader:
 1. Restart pod in a `rollout` on change in linked/related `ConfigMaps` or `Secrets`
 
 This site contains more details on how Reloader works. For an overview, please see the repository's [README file](https://github.com/stakater/Reloader/blob/master/README.md).
+
+---
+
+<div align="center">
+
+[![💖 Sponsor our work](https://img.shields.io/badge/Sponsor%20Our%20Work-FF8C00?style=for-the-badge&logo=github-sponsors&logoColor=white)](https://github.com/sponsors/stakater?utm_source=docs&utm_medium=footer&utm_campaign=reloader)
+
+<p>
+Your support funds maintenance, security updates, and new features for Reloader, plus continued investment in other open source tools.
+</p>
+
+</div>
+
+---