docs: add usage information

Author: brenodt

README.md

@@ -3,9 +3,63 @@ Self-contained development utilities. Includes tmux, nvim, git & more 👨
 
 ## Usage
 
+To start an ephemeral Docker image locally:
 ```console
-docker pull ghcr.io/brenodt/devbox:main
-
 docker run -it --rm ghcr.io/brenodt/devbox:main
 ```
 
+## Example K8S Pod definition
+
+Here's an example pod definition using this container:
+```yaml
+# pod-helper.yaml
+#
+# This is a helper pod to debug and work locally from within the cluster,
+# with access to their volume mounts and secrets.
+#
+---
+apiVersion: v1
+kind: Pod
+metadata:
+  labels:
+    run: live-helper
+  name: live-helper
+  namespace: default
+spec:
+  containers:
+    - command:
+        - tail
+        - -f
+        - /dev/null
+      image: ghcr.io/brenodt/devbox:main
+      imagePullPolicy: Always
+      name: live-helper
+      envFrom:
+        - secretRef:
+            # Connecting to an Opaque secret
+            name: shared-cronjob-config
+      resources:
+        requests:
+          cpu: 100m
+          memory: 128Mi
+        limits:
+          cpu: 150m
+          memory: 256Mi
+      volumeMounts:
+        # Connecting to volumes from the cluster
+        - name: dump-volume
+          mountPath: /dump
+
+  volumes:
+    - name: dump-volume
+      persistentVolumeClaim:
+        claimName: cronjob-dumps-pvc
+
+```
+
+To apply and connect, run:
+```console
+kubectl apply -f pod-helper.yaml
+kubectl exec pod-helper -it -- /bin/bash
+```
+