Add Relica as sponsor on readme

README.md

@@ -25,6 +25,12 @@ Caddy is a **production-ready** open-source web server that is fast, easy to use
 
 Available for Windows, Mac, Linux, BSD, Solaris, and [Android](https://github.com/mholt/caddy/wiki/Running-Caddy-on-Android).
 
+<p align="center">
+	<b>Thanks to our special sponsor:</b>
+	<br><br>
+	<a href="https://relicabackup.com"><img src="https://caddyserver.com/resources/images/sponsors/relica.png" width="220" alt="Relica - Cross-platform file backup to the cloud, local disks, or other computers"></a>
+</p>
+
 ## Menu
 
 - [Features](#features)