docs: redis docs (#4316)

apps/docs/app/self-hosting/cluster-setup/page.mdx

@@ -0,0 +1,54 @@
+export const metadata = {
+  title: "Cluster Setup for Formbricks",
+  description: "Learn how to set up Formbricks in a multi-instance cluster configuration for high availability and scalability.",
+};
+
+#### Self-Hosting
+
+# Cluster Setup
+
+<Note>
+  Running Formbricks in a multi-instance cluster configuration is an Enterprise Edition feature and requires an enterprise license key.
+</Note>
+
+## Overview
+
+Running Formbricks as a cluster of multiple instances offers several key advantages:
+
+- **High Availability**: Ensure your surveys remain accessible even if some instances fail
+- **Load Distribution**: Handle higher traffic by distributing requests across multiple instances
+- **Scalability**: Easily scale horizontally by adding more instances as your needs grow
+- **Zero-Downtime Updates**: Rolling updates without service interruption
+
+## Requirements
+
+To run Formbricks in a cluster setup, you'll need:
+
+- Enterprise Edition license key
+- Shared PostgreSQL database
+- Shared Redis cache for session management and caching
+- Load balancer to distribute traffic
+
+## Redis Configuration
+
+<Note>
+  Redis integration is an Enterprise Edition feature and requires an enterprise license key.
+</Note>
+
+Configure Redis by adding the following environment variables to your instances:
+
+```sh {{ title: 'env file' }}
+REDIS_URL=redis://your-redis-host:6379
+REDIS_HTTP_URL=http://your-redis-host:8000
+```
+
+## Coming Soon
+
+We're working on comprehensive Kubernetes deployment instructions to make cluster setup even easier. This will include:
+
+- Kubernetes manifests
+- Helm charts
+- Detailed scaling configurations
+- Production-ready deployment examples
+
+Stay tuned for updates.

apps/docs/lib/navigation.ts

@@ -143,6 +143,7 @@ export const navigation: Array<NavGroup> = [
       { title: "Configuration", href: "/self-hosting/configuration" },
       { title: "Integrations", href: "/self-hosting/integrations" },
       { title: "License", href: "/self-hosting/license" },
+      { title: "Cluster Setup", href: "/self-hosting/cluster-setup" },
     ],
   },
   {