Add how-to/integration guide: Deploy a production API and gateway wit…

…h APIOps using Argo CD and ngrok (#835)

As I was writing a blog post about APIOps and ngrok, I realized the
technical implementation deserved its own home in the docs—for one, it
was far too complex for a blog post, and second, it's a really nice
integration to have formally documented for future use.

This guide details how to deploy an example API with an APIOps-esque
workflow using the ngrok Kubernetes Operator, Kubernetes Gateway API,
Argo CD, and a public Git repository.

docs/integrations/argocd/index.mdx

@@ -0,0 +1,15 @@
+---
+name: argocd
+title: Argo CD Integration Hub
+sidebar_label: Argo CD
+description: |
+  Argo CD is the leading declarative GitOps continuous delivery tool for Kubernetes. With Argo CD, you store all your applications, configurations, and environments in one or more Git repositories so that your deployment and lifecycle management processes are automated, auditable, and repeatable.
+excerpt: |
+  Quickly add ingress to apps and APIs running on Kubernetes clusters with GitOps/APIOps deployments.
+---
+
+import IntegrationPageList from "@site/src/components/IntegrationPageList";
+
+<p>{frontMatter.description}</p>
+
+<IntegrationPageList name={frontMatter.name} />