chore: add harmony plugin

Author: Ian2012

contrib/redwood/plugins.yml

@@ -33,6 +33,14 @@
     Drydock is an opinionated tool offering a set of Tutor plugins aiming to provide features
     that enhance the operation of Open edX installations in Kubernetes.
 
+- 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: meilisearch
   src: -e git+https://github.com/open-craft/[email protected]#egg=tutor-meilisearch
   url: https://github.com/open-craft/tutor-contrib-meilisearch