add documentation about automating release using krew-release-bot (#468)

* add documentation about automating release using krew-release-bot

* update doc

* capitalize and wrap lines

* update doc

* fix doc wording

docs/DEVELOPER_GUIDE.md

@@ -333,5 +333,12 @@ Ideally, the `version` specified should match the release tag of the plugin.
 This helps users and maintainers to easily identify which version of the plugin
 they have installed.
 
+### Automate releasing new versions on krew-index
+
+You can use Github Actions to publish new release of your Krew plugin. 
+`krew-release-bot` is a Github Action to automatically bump the version in 
+`krew-index` repo. 
+Refer to the [krew-release-bot](https://github.com/rajatjindal/krew-release-bot) documentation for details.
+
 [index]: https://github.com/kubernetes-sigs/krew-index
 [plugins]: https://kubernetes.io/docs/tasks/extend-kubectl/kubectl-plugins/