add comprehensive documentation (#9537)

docs/misc/cloud-init.func/CLOUD_INIT_FUNC_USAGE_EXAMPLES.md

@@ -0,0 +1,17 @@
+# cloud-init.func Usage Examples
+
+Examples for VM cloud-init configuration.
+
+### Example: Basic Cloud-Init
+
+```bash
+#!/usr/bin/env bash
+
+generate_cloud_init > cloud-init.yaml
+setup_ssh_keys "$VMID" "$SSH_KEY"
+apply_cloud_init "$VMID" cloud-init.yaml
+```
+
+---
+
+**Last Updated**: December 2025