docs: update operator deployment

docs/operator-manual/gateway.md

@@ -0,0 +1,88 @@
+---
+title: Gateway
+layout: default
+parent: Operator Manual
+nav_order: 2
+---
+
+## Gateway
+The **Gateway** serves as the entry point to the server, handling and routing incoming traffic.
+
+### Installation Details
+
+When a Gateway is installed, it automatically creates the following Kubernetes resources, all with the same name as the Gateway:
+
+- **Service**
+- **ConfigMap**
+- **Deployment**
+
+### Service Ports
+
+The service exposes the following ports:
+
+- **HTTP**: `8080`
+- **HTTPS**: `8443`
+
+### Exposing the Gateway Outside the Cluster
+
+To expose your Gateway outside the cluster, you have the following options:
+
+1. **Create an Ingress resource**:  
+   Configure an Ingress to route external traffic to your Gateway.
+
+2. **Change the Service Type**:  
+   Patch the Gateway's service to change its type (e.g., to `LoadBalancer` or `NodePort`) for external accessibility.
+
+A simple example of gateway
+
+```yaml
+apiVersion: gomaproj.github.io/v1beta1
+kind: Gateway
+metadata:
+  labels: {}
+  name: gateway-sample
+spec:
+  # The version of Goma Gateway
+  # See: https://github.com/jkaninda/goma-gateway/releases
+  gatewayVersion: latest
+  ## Server config
+  server:
+    # Kubernetes tls secret name
+    tlsSecretName: '' #Optional, tls-secret
+    #Redis configs for distributed rate limiting across multiple instances
+    redis:
+        addr: '' #Optional, redis:6379
+        password: '' #Optional, password
+    writeTimeout: 10
+    readTimeout: 15
+    idleTimeout: 30
+    logLevel: info
+    disableHealthCheckStatus: false
+    disableKeepAlive: false
+    enableMetrics: true
+  replicaCount: 1
+  resources:
+    limits:
+      cpu: 200m
+      memory: 512Mi
+    requests:
+      cpu: 100m
+      memory: 128Mi
+  # Enable auto scaling
+  autoScaling:
+    enabled: true
+    minReplicas: 2
+    maxReplicas: 5
+    targetCPUUtilizationPercentage: 80
+    targetMemoryUtilizationPercentage: 80
+  affinity: {}
+```
+### Delete gateway
+```shell
+kubectl delete gateway (gatewayName)
+```
+Or
+
+```shell
+kubectl delete gateways.gomaproj.github.io (gatewayName)
+```