fix(KONFLUX-5917): adding tekton example of using secret

Signed-off-by: Kasem Alem <[email protected]>

Author: Kasem Alem

docs/modules/ROOT/pages/how-tos/configuring/creating-secrets.adoc

@@ -47,6 +47,28 @@ Some container builds may use parent images from registries that require authent
 . Enter the password for the registry in **Password**.
 . Click **Add secret**.
 
+.Example using registry pull secret in tekton task 
+
+[source, yaml]
+----
+apiVersion: tekton.dev/v1beta1
+kind: TaskRun
+metadata:
+  name: build-container
+spec:
+  taskRef:
+    name: build-container
+  params:
+    - name: image
+      value: registry.redhat.io/my-image:latest
+  workspaces:
+    - name: source
+      subPath: src
+  volumes:
+    - name: registry-credentials
+      secret:
+        secretName: registry.redhat.io
+----
 
 [NOTE]
 ====