Add YouTube link on index page

Add a link to the YouTube video from the index page; it will also
be linked from the new page I'm about to create.

doc/development/agent/index.md

@@ -72,6 +72,10 @@ graph TB
   - (Optional) Sending notifications through ActionCable for events received from `agentk`.
   - Polling manifest repositories for [GitOps support](https://gitlab.com/gitlab-org/cluster-integration/gitlab-agent/-/blob/master/doc/gitops.md) by communicating with Gitaly.
 
+<i class="fa fa-youtube-play youtube" aria-hidden="true"></i>
+To learn more about how the repository is structured, see
+[GitLab Kubernetes Agent repository overview](https://www.youtube.com/watch?v=j8CyaCWroUY).
+
 ## Guiding principles
 
 GitLab prefers to add logic into `kas` rather than `agentk`. `agentk` should be kept

doc/development/agent/local.md

+---
+stage: Configure
+group: Configure
+info: To determine the technical writer assigned to the Stage/Group associated with this page, see https://about.gitlab.com/handbook/engineering/ux/technical-writing/#designated-technical-writers
+---
+
+# Run the Kubernetes Agent locally **(PREMIUM ONLY)**
+
+You can run `kas` and `agentk` locally to test the [Kubernetes Agent](index.md) yourself.
+
+1. Create a `cfg.yaml` file from the contents of
+   [`kas_config_example.yaml`](https://gitlab.com/gitlab-org/cluster-integration/gitlab-agent/-/blob/master/doc/kas_config_example.yaml), or this example:
+
+   ```yaml
+   listen_agent:
+     network: tcp
+     address: 127.0.0.1:8150
+     websocket: false
+   gitlab:
+     address: http://localhost:3000
+     authentication_secret_file: /Users/tkuah/code/ee-gdk/gitlab/.gitlab_kas_secret
+   agent:
+     gitops:
+       poll_period: "10s"
+   ```
+
+1. Create a `token.txt`. This is the token for
+   [the agent you created](../../user/clusters/agent/index.md#create-an-agent-record-in-gitlab). This file must not contain a newline character. You can create the file with this command:
+
+   ```shell
+   echo -n "<TOKEN>" > token.txt
+   ```
+
+1. Start the binaries with the following commands:
+
+   ```shell
+   # Need GitLab to start
+   gdk start
+   # Stop GDK's version of kas
+   gdk stop gitlab-k8s-agent
+
+   # Start kas
+   bazel run //cmd/kas -- --configuration-file="$(pwd)/cfg.yaml"
+   ```
+
+1. In a new terminal window, run this command to start agentk:
+
+   ```shell
+   bazel run //cmd/agentk -- --kas-address=grpc://127.0.0.1:8150 --token-file="$(pwd)/token.txt"
+   ```
+
+You can also inspect the
+[Makefile](https://gitlab.com/gitlab-org/cluster-integration/gitlab-agent/-/blob/master/Makefile)
+for more targets.
+
+<i class="fa fa-youtube-play youtube" aria-hidden="true"></i>
+To learn more about how the repository is structured, see
+[GitLab Kubernetes Agent repository overview](https://www.youtube.com/watch?v=j8CyaCWroUY).