Add link to doc for Helm Stop plugin

Link added to
https://github.com/helm/helm/blob/master/docs/related.md#helm-plugins

docs/related.md

@@ -45,6 +45,7 @@ or [pull request](https://github.com/kubernetes/helm/pulls).
 - [helm-k8comp](https://github.com/cststack/k8comp) - Plugin to create Helm Charts from hiera using k8comp
 - [helm-hashtag](https://github.com/balboah/helm-hashtag) - Plugin for tracking docker tag hash digests as values
 - [helm-unittest](https://github.com/lrills/helm-unittest) - Plugin for unit testing chart locally with YAML
+- [helm-stop](https://github.com/IBM/helm-stop) - Plugin for stopping a release pods
 
 We also encourage GitHub authors to use the [helm-plugin](https://github.com/search?q=topic%3Ahelm-plugin&type=Repositories)
 tag on their plugin repositories.