Add contributors.jenkins.io announcement to jumbotron (#6879)

* Add contributors.jenkins.io announcement

* Update text

* Update content/_data/indexpage/carousel.yml

---------

Co-authored-by: Kevin Martens <99040580+kmartens27@users.noreply.github.com>

content/_data/indexpage/carousel.yml

@@ -1,3 +1,14 @@
+- :href: https://contributors.jenkins.io/
+  :title: Meet the driving forces
+  :intro: behind Jenkins 
+    as we showcase the top contributors shaping the
+    future of continuous integration and delivery.
+  :image:
+    :src: images/logos/jenkins/jenkins.png
+    :height: 285px
+  :call_to_action:
+    :text: More info
+    :href: https://contributors.jenkins.io/
 # Case Studies
 - :href: https://stories.jenkins.io/
   :title: Jenkins Stories!