Add Fider Guide

Added the official guide link for fider installation

Author: Cizzl

docs/services/fider.md

@@ -10,6 +10,10 @@ description: "Here you can find the documentation for hosting Fider with Coolify
 
 Fider is a feedback portal for feature requests and suggestions. Give your customers a voice and let them tell you what they need. Spend less time guessing and more time building the right product.
 
+## How to setup
+
+See the official [Fider + Coolify guide](https://docs.fider.io/hosting-coolify?utm_source=coolify.io)
+
 ## Links
 
 - [The official website ›](https://fider.io?utm_source=coolify.io)