docs: update operator deployment

docs/operator-manual/installation.md

@@ -0,0 +1,28 @@
+---
+title: Installation
+layout: default
+parent: Operator Manual
+nav_order: 1
+---
+
+# Installation
+
+## Kubernetes Advanced deployment using CRDs and an Operator
+
+**Install the CRDs and Operator into the cluster:**
+
+```sh
+kubectl apply -f https://raw.githubusercontent.com/jkaninda/goma-operator/main/dist/install.yaml
+```
+
+### Resources
+
+- Gateway
+- Middleware
+- Route
+
+### Resources order
+
+- Gateway
+- Middleware
+- Route