chore: add harmony plugin

Author: Ian2012

contrib/redwood/plugins.yml

@@ -7,6 +7,14 @@
     Tutor plugin to enable execution of untrusted code in secure sandboxes.
     In particular, this plugin is required to run Python-evaluated input XBlocks.
 
+- name: k8s_harmony
+  src: tutor-plugin-harmony>=18.0.0,<19.0.0
+  url: https://github.com/openedx/openedx-k8s-harmony
+  author: eduNEXT <[email protected]>, OpenCraft <[email protected]>, and contributors
+  maintainer: OpenCraft <[email protected]>
+  description: |
+    Tutor plugin to deploy multiple Open edX instances on a single cluster.
+
 - name: pod-autoscaling
   src: -e git+https://github.com/eduNEXT/[email protected]#egg=tutor-contrib-pod-autoscaling
   url: https://github.com/eduNEXT/tutor-contrib-pod-autoscaling